@comment{ $Source: e:\\cvsroot/ARM/Source/pre_containers.mss,v $ } @comment{ $Revision: 1.28 $ $Date: 2005/05/20 05:49:41 $ $Author: Randy $ } @Part(precontainers, Root="ada.mss") @Comment{$Date: 2005/05/20 05:49:41 $} @LabeledAddedClause{Version=[2],Name=[Containers]} @begin{Intro} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[This clause presents the specifications of the package Containers and several child packages, which provide facilities for storing collections of elements.]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[A variety of sequence and associative containers are provided. Each container includes a @i{cursor} type. A cursor is a reference to an element within a container. Many operations on cursors are common to all of the containers.@PDefn2{Term=[cursor],Sec=[for a container]} @Defn2{Term=[container],Sec=[cursor]}]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Within this clause we provide Implementation Advice for the desired average or worst case time complexity of certain operations on a container. This advice is expressed using a big-O notation. A complexity of O(f(N)), presuming f is some function of a length parameter N and t(N) is the time the operation takes (on average or worst case, as specified) for the length N, means that there exists a finite A such that for any N, t(N)/f(N) < A. @Defn{big-O notation}@Defn{O(f(N))}]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Of course, an implementation can do better than a specified O(f(N)): for example, O(1) meets the requirements for O(log N).]} @end{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[If the advice suggests that the complexity should be less than O(f(N)), then for any arbitrarily small positive real D, there should exist a positive integer M such that for all N > M, t(N)/f(N) < D.]} @end{Intro} @begin{Metarules} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[This clause provides a number of useful containers for Ada. Only the most useful containers are provided. Ones that are relatively easy to code, redundant, or rarely used are omitted from this set, even if they are generally included in containers libraries.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The containers packages are modeled on the Standard Template Library (STL), an algorithms and data structure library popularized by Alexander Stepanov, and included in the C++ standard library. The structure and terminology differ from the STL where that better maps to common Ada usage. For instance, what the STL calls @lquotes@;iterators@rquotes@; are called @lquotes@;cursors@rquotes@; here.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Leading],Text=[The following major non-limited containers are provided:]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[(Expandable) Vectors of any non-limited type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Doubly-linked Lists of any non-limited type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Hashed Maps keyed by any non-limited hashable type, and containing any non-limited type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Ordered Maps keyed by any non-limited ordered type, and containing any non-limited type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Hashed Sets of any non-limited hashable type; and]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Ordered Sets of any non-limited ordered type.]} @end{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Separate versions for definite and indefinite element types are provided, as those for definite types can be implemented more efficiently.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Each container includes a cursor, which is a reference to an element within a container. Cursors generally remain valid as long as the container exists and the element referenced is not deleted. Many operations on cursors are common to all of the containers. This makes it possible to write generic algorithms that work on any kind of container.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The containers packages are structured so that additional packages can be added in the future. Indeed, we hope that these packages provide the basis for a more extensive secondary standard for containers.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[If containers with similar functionality (but different performance characteristics) are provided (by the implementation or by a secondary standard), we suggest that a prefix be used to identify the class of the functionality: "Ada.Containers.Bounded_Sets" (for a set with a maximum number of elements); "Ada.Containers.Protected_Maps" (for a map which can be accessed by multiple tasks at one time); "Ada.Containers.Persistent_Vectors" (for a persistent vector which continues to exist between executions of a program) and so on.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Leading],Text=[Note that the language already includes several requirements that are important to the use of containers. These include:]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Library packages must be reentrant @en multiple tasks can use the packages as long as they operate on separate containers. Thus, it is only necessary for a user to protect a container if a single container needs to be used by multiple tasks.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Language-defined types must stream "properly". That means that the stream attributes can be used to implement persistence of containers when necessary, and containers can be passed between partitions of a program.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Equality of language-defined types must compose @lquotes@;properly@rquotes@;. This means that the version of "=" directly used by users is the same one that will be used in generics and in predefined equality operators of types with components of the containers and/or cursors. This prevents the abstraction from breaking unexpectedly.]} @end{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[If a container's element type is controlled, the point at which the element is finalized will depend on the implementation of the container. We do not specify precisely where this will happen (it will happen no later than the finalization of the container, of course) in order to give implementation's flexibility to cache, block, or split the nodes of the container. In particular, Delete does not necessarily finalize the element; the implementation may (or may not) hold the space for reuse. (The reference implementations show this well, as Delete for a Vector does not finalize the element, while Delete for an Ordered_Set does.)]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This is not likely to be a hardship, as the element type has to be non-limited. Types used to manage scarce resources generally need to be limited. Otherwise, the amount of resources needed is hard to control, as the language allows a lot of variation in the number or order of adjusts/finalizations. For common uses of non-limited controlled types such as managing storage, the types already have to manage arbitrary copies.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The use of controlled type also brings up the possibility of failure of finalization (and thus deallocation) of an element. This is a @lquotes@;serious bug@rquotes@;, as AI-179 puts it, so we don't try to specify what happens in that case. The implementation should propagate the exception.]} @end{Metarules} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[It is expected that exceptions propagated from these operations do not damage containers. That is, if Storage_Error is propagated because of an allocation failure, or Constraint_Error is propagated by the assignment of elements, the container can continue to be used without further exceptions. The intent is that it should be possible to recover from errors without losing data. We don't try to state this formally in most cases, because it is hard to define precisely what is and is not allowed behavior.]} @end{ImplNote} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[When this clause says that the behavior of something is unspecified@PDefn{unspecified}, we really mean that any result of executing Ada code short of erroneous execution is allowed. We do not mean that memory not belonging to the parameters of the operation can be trashed. When we mean to allow erroneous behavior, we specifically say that execution is erroneous. All this means if the containers are written in Ada is that checks should not be suppressed or removed assuming some behavior of other code, and that the implementation should take care to avoid creating internal dangling accesses by assuming behavior from generic formals that can't be guaranteed. We don't try to say this normatively because it would be fairly complex, and implementers are unlikely to increase their support costs by fielding implementations that are unstable if given buggy hash functions, et. al.]} @end{ImplNote} @begin{Extend95} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn{extensions to Ada 95} This clause is new. It just provides an introduction to the following subclauses.]} @end{Extend95} @LabeledAddedSubclause{Version=[2],Name=[The Package Containers]} @begin{Intro} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The package Containers is the root of the containers subsystem.]} @end{Intro} @begin{StaticSem} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],KeepNext=[T],Type=[Leading],Text=[The library package Containers has the following declaration:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{package} Ada.Containers @key{is}@ChildUnit{Parent=[Ada],Child=[Containers]} @key{pragma} Pure(Containers);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{type} @AdaTypeDefn{Hash_Type} @key{is mod} @i;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{type} Count_Type @key{is range} 0 .. @i;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{end} Ada.Containers;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-02]} @ChgAdded{Version=[2],Text=[Hash_Type represents the range of the result of a hash function. Count_Type represents the (potential or actual) number of elements of a container.]} @ChgImpldef{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[The value of Containers.Hash_Type'Modulus. The value of Containers.Count_Type'Last.]}]} @end{StaticSem} @begin{ImplAdvice} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Hash_Type'Modulus should be at least 2**32. Count_Type'Last should be at least 2**31@en@;1.]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[Containers.Hash_Type'Modulus should be at least 2**32. Containers.Count_Type'Last should be at least 2**31@en@;1.]}]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This is not a requirement so that these types can be declared properly on machines with native sizes that are not 32 bits. For instance, a 24-bit target could use 2**24 for Hash_Type'Modulus.]} @end{Discussion} @end{ImplAdvice} @begin{Extend95} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn{extensions to Ada 95} The package Ada.Containers is new.]} @end{Extend95} @LabeledAddedSubclause{Version=[2],Name=[The Package Containers.Vectors]} @begin{Intro} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The language-defined generic package Containers.Vectors provides private types Vector and Cursor, and a set of operations for each type. A vector container allows insertion and deletion at any position, but it is specifically optimized for insertion and deletion at the high end (the end with the higher index) of the container. A vector container also provides random access to its elements.@Defn{vector container} @Defn2{Term=[container],Sec=[vector]}]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@Pdefn2{Term=[length], Sec=(of a vector container)} @Pdefn2{Term=[capacity], Sec=(of a vector)} A vector container behaves conceptually as an array that expands as necessary as items are inserted. The @i{length} of a vector is the number of elements that the vector contains. The @i{capacity} of a vector is the maximum number of elements that can be inserted into the vector prior to it being automatically expanded.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@Pdefn2{Term=[empty element], Sec=(of a vector)} A vector container may contain @i{empty elements}. Empty elements do not have a specified value.]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ Vectors are not intended to be sparse (that is, there are elements at all defined positions). Users are expected to use other containers (like a Map) when they need sparse structures (there is a Note to this effect at the end of this subclause).]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ The internal array is a conceptual model of a vector. There is no requirement for an implementation to be a single contiguous array.]} @end{Implnote} @end{Intro} @begin{StaticSem} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],KeepNext=[T],Type=[Leading],Text=[The generic library package Containers.Vectors has the following declaration:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{generic} @key{type} Index_Type @key{is range} <>; @key{type} Element_Type @key{is private}; @key{with function} "=" (Left, Right : Element_Type) @key{return} Boolean @key{is} <>; @key{package} Ada.Containers.Vectors @key{is}@ChildUnit{Parent=[Ada.Containers],Child=[Vectors]} @key{pragma} Preelaborate(Vectors);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{subtype} @AdaDefn{Extended_Index} @key{is} Index_Type'Base @key{range} Index_Type'First-1 .. Index_Type'Min (Index_Type'Base'Last - 1, Index_Type'Last) + 1; @AdaDefn{No_Index} : @key{constant} Extended_Index := Extended_Index'First;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{subtype} @AdaDefn{Index_Subtype} @key{is} Index_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{type} @AdaTypeDefn{Vector} @key{is tagged private}; @key{pragma} Preelaborable_Initialization(Vector);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{type} @AdaTypeDefn{Cursor} @key{is private}; @key{pragma} Preelaborable_Initialization(Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @AdaDefn{Empty_Vector} : @key{constant} Vector;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @AdaDefn{No_Element} : @key{constant} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{To_Vector} (Length : Count_Type) @key{return} Vector;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{To_Vector} (New_Item : Element_Type; Length : Count_Type) @key{return} Vector;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "&" (Left, Right : Vector) @key{return} Vector;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "&" (Left : Vector; Right : Element_Type) @key{return} Vector;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "&" (Left : Element_Type; Right : Vector) @key{return} Vector;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "&" (Left, Right : Element_Type) @key{return} Vector;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "=" (Left, Right : Vector) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Capacity} (Container : Vector) @key{return} Count_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Reserve_Capacity} (Container : @key{in out} Vector; Capacity : @key{in} Count_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Length} (Container : Vector) @key{return} Count_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Is_Empty} (Container : Vector) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Clear} (Container : @key{in out} Vector);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{To_Cursor} (Container : Vector; Index : Extended_Index) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{To_Index} (Position : Cursor) @key{return} Extended_Index;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Element} (Container : Vector; Index : Index_Type) @key{return} Element_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Element} (Position : Cursor) @key{return} Element_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Query_Element} (Container : @key{in} Vector; Index : @key{in} Index_Type; Process : @key{not null access procedure} (Element : @key{in} Element_Type));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Query_Element} (Position : @key{in} Cursor; Process : @key{not null access procedure} (Element : @key{in} Element_Type));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Update_Element} (Container : @key{in} Vector; Index : @key{in} Index_Type; Process : @key{not null access procedure} (Element : @key{in out} Element_Type));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Update_Element} (Position : @key{in} Cursor; Process : @key{not null access procedure} (Element : @key{in out} Element_Type));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Replace_Element} (Container : @key{in} Vector; Index : @key{in} Index_Type; By : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Replace_Element} (Position : @key{in} Cursor; By : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Assign} (Target : @key{in out} Vector; Source : @key{in} Vector);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Move} (Target : @key{in out} Vector; Source : @key{in out} Vector);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert} (Container : @key{in out} Vector; Before : @key{in} Extended_Index; New_Item : @key{in} Vector);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert} (Container : @key{in out} Vector; Before : @key{in} Cursor; New_Item : @key{in} Vector);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert} (Container : @key{in out} Vector; Before : @key{in} Cursor; New_Item : @key{in} Vector; Position : @key{out} Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert} (Container : @key{in out} Vector; Before : @key{in} Extended_Index; New_Item : @key{in} Element_Type; Count : @key{in} Count_Type := 1);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert} (Container : @key{in out} Vector; Before : @key{in} Cursor; New_Item : @key{in} Element_Type; Count : @key{in} Count_Type := 1);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert} (Container : @key{in out} Vector; Before : @key{in} Cursor; New_Item : @key{in} Element_Type; Position : @key{out} Cursor; Count : @key{in} Count_Type := 1);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Prepend} (Container : @key{in out} Vector; New_Item : @key{in} Vector);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Prepend} (Container : @key{in out} Vector; New_Item : @key{in} Element_Type; Count : @key{in} Count_Type := 1);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Append} (Container : @key{in out} Vector; New_Item : @key{in} Vector);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Append} (Container : @key{in out} Vector; New_Item : @key{in} Element_Type; Count : @key{in} Count_Type := 1);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert_Space} (Container : @key{in out} Vector; Before : @key{in} Extended_Index; Count : @key{in} Count_Type := 1);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert_Space} (Container : @key{in out} Vector; Before : @key{in} Cursor; Position : @key{out} Cursor; Count : @key{in} Count_Type := 1);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Set_Length} (Container : @key{in out} Vector; Length : @key{in} Count_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete} (Container : @key{in out} Vector; Index : @key{in} Extended_Index; Count : @key{in} Count_Type := 1);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete} (Container : @key{in out} Vector; Position : @key{in out} Cursor; Count : @key{in} Count_Type := 1);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete_First} (Container : @key{in out} Vector; Count : @key{in} Count_Type := 1);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete_Last} (Container : @key{in out} Vector; Count : @key{in} Count_Type := 1);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{First_Index} (Container : Vector) @key{return} Index_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{First} (Container : Vector) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{First_Element} (Container : Vector) @key{return} Element_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Last_Index} (Container : Vector) @key{return} Extended_Index;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Last} (Container : Vector) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Last_Element} (Container : Vector) @key{return} Element_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Swap} (Container : @key{in} Vector; I, J : @key{in} Index_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Swap} (I, J : @key{in} Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{generic} @key{with function} "<" (Left, Right : Element_Type) @key{return} Boolean is <>; @key{package} @AdaDefn{Generic_Sorting} @key{is}]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Is_Sorted} (Container : Vector) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Sort} (Container : @key{in out} Vector);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Merge} (Target : @key{in out} Vector; Source : @key{in out} Vector);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{end} Generic_Sorting;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Find_Index} (Container : Vector; Item : Element_Type; Index : Index_Type := Index_Type'First) @key{return} Extended_Index;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Find} (Container : Vector; Item : Element_Type; Position : Cursor := No_Element) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Reverse_Find_Index} (Container : Vector; Item : Element_Type; Index : Index_Type := Index_Type'Last) @key{return} Extended_Index;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Reverse_Find} (Container : Vector; Item : Element_Type; Position : Cursor := No_Element) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Contains} (Container : Vector; Item : Element_Type) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Next} (Position : Cursor) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Previous} (Position : Cursor) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Next} (Position : @key{in out} Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Previous} (Position : @key{in out} Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Has_Element} (Position : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Iterate} (Container : @key{in} Vector; Process : @key{not null access procedure} (Position : @key{in} Cursor));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Reverse_Iterate} (Container : @key{in} Vector; Process : @key{not null access procedure} (Position : @key{in} Cursor));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{private}]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ ... -- @RI[not specified by the language]]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{end} Ada.Containers.Vectors;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The type Vector is used to represent vectors. The type Vector needs finalization (see @RefSecNum{User-Defined Assignment and Finalization}).]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Empty_Vector represents the empty vector object. It has a length of 0. If an object of type Vector is not otherwise initialized, it is initialized to the same value as Empty_Vector.]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[No_Element represents a cursor that designates no element. If an object of type Cursor is not otherwise initialized, it is initialized to the same value as No_Element.]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[No_Index represents a position that does not correspond to any element. The subtype Extended_Index includes the indices covered by Index_Type plus the value No_Index and, if it exists, the successor to the Index_Type'Last.]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[We require the existence of Index_Type'First @en 1, so that No_Index and Last_Index of an empty vector is well-defined. We don't require the existence of Index_Type'Last + 1, as it is only used as the position of insertions (and needs to be allowed only when inserting an empty vector).]} @end{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[@Defn2{Term=[tamper with cursors],Sec=[of a vector]} Some operations are assumed to work on a constant set of elements. For such an operation, a subprogram is said to @i of a vector object @i if:]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it inserts or deletes elements of @i, that is, it calls the Insert, Insert_Space, Clear, Delete, or Set_Length procedures with @i as a parameter; or]} @begin{Honest} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Operations which are defined to be equivalent to a call on one of these operations also are included. Similarly, operations which call one of these as part of their definition are included.]} @end{Honest} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it finalizes @i; or]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it calls the Move procedure with @i as a parameter.]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Swap, Sort, and Merge copy elements rather than reordering them, so they don't tamper with cursors.]} @end{Discussion} @end{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[@Defn2{Term=[tamper with elements],Sec=[of a vector]} Some operations are assumed to not replace elements. For such an operation, a subprogram is said to @i of a vector object @i if:]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it tampers with cursors of @i; or]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it replaces one or more elements of @i, that is, it calls the Replace_Element or Swap procedures or the Sort or Merge procedures of an instance of Generic_Sorting with @i as a parameter.]} @begin{Reason} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Complete replacement of an element can cause its memory to be deallocated while another operation is holding onto a reference to it. That can't be allowed. However, a simple modification of (part of) an element is not a problem, so Update_Element does not cause a problem.]} @end{Reason} @end{Itemize} @begin{DescribeCode} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} To_Vector (Length : Count_Type) @key{return} Vector;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns a vector with a length of Length, filled with empty elements.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} To_Vector (New_Item : Element_Type; Length : Count_Type) @key{return} Vector;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns a vector with a length of Length, filled with elements initialized to the value New_Item.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} "&" (Left, Right : Vector) @key{return} Vector;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns a vector comprising the elements of Left followed by the elements of Right.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} "&" (Left : Vector; Right : Element_Type) @key{return} Vector;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns a vector comprising the elements of Left followed by the element Right.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} "&" (Left : Element_Type; Right : Vector) @key{return} Vector;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns a vector comprising the element Left followed by the elements of Right.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} "&" (Left, Right : Element_Type) @key{return} Vector;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns a vector comprising the element Left followed by the element Right.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} "=" (Left, Right : Vector) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Left and Right denote the same vector object, then the function returns True. If Left and Right have different lengths, then the function returns False. Otherwise, it compares each element in Left to the corresponding element in Right using the generic formal equality operator; if element equality returns False, then the function returns False. If the function has not returned a result after checking all of the elements, it returns True. Any exception raised during evaluation of element equality is propagated.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Capacity (Container : Vector) @key{return} Count_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns the capacity of Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Reserve_Capacity (Container : @key{in out} Vector; Capacity : @key{in} Count_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Reserve_Capacity allocates new internal data structures such that the length of the resulting vector can become at least the value Capacity without requiring an additional call to Reserve_Capacity, and is large enough to hold the current length of Container. Reserve_Capacity then copies the elements into the new data structures and deallocates the old data structures. Any exception raised during allocation is propagated and Container is not modified.]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Expanding the internal array can be done by allocating a new, longer array, copying the elements, and deallocating the original array. This may raise Storage_Error, or cause an exception from a controlled subprogram. We require that a failed Reserve_Capacity does not lose any elements if an exception occurs, but we do not require a specific order of evaluations or copying.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This routine is used to preallocate the internal array to the specified capacity such that future Inserts do not require memory allocation overhead. Therefore, the implementation should allocate the needed memory to make that true at this point, even though the visible semantics could be preserved by waiting until the memory is needed. This doesn't apply to the indefinite element container, because elements will have to be allocated individually.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The implementation does not have to contract the internal array if the capacity is reduced, as any capacity greater than or equal to the specified capacity is allowed.]} @end{Discussion} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Length (Container : Vector) @key{return} Count_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns the number of elements in Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Is_Empty (Container : Vector) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Length (Container) = 0.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Clear (Container : @key{in out} Vector);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Removes all the elements from Container. The capacity of Container does not change.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} To_Cursor (Container : Vector; Index : Extended_Index) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Index is not in the range First_Index (Container) .. Last_Index (Container), then No_Element is returned. Otherwise, a cursor designating the element at position Index in Container is returned.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} To_Index (Position : Cursor) @key{return} Extended_Index;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position is No_Element, No_Index is returned. Otherwise, the index (within its containing vector) of the element designated by Cursor is returned.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This implies that the index is determinable from a bare cursor alone. The basic model is that a vector cursor is implemented as a record containing an access to the vector container and an index value. This does constrain implementations, but it also allows all of the cursor operations to be defined in terms of the corresponding index operation (which should be primary for a vector).]} @end{Ramification} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Element (Container : Vector; Index : Index_Type) @key{return} Element_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Index is not in the range First_Index (Container) .. Last_Index (Container), then Constraint_Error is propagated. Otherwise, Element returns the element at position Index.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Element (Position : Cursor) @key{return} Element_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element, then Constraint_Error is propagated. Otherwise, Element returns the element designated by Position.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Query_Element (Container : @key{in} Vector; Index : @key{in} Index_Type; Process : @key{not null access} @key{procedure} (Element : @key{in} Element_Type));]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Index is not in the range First_Index (Container) .. Last_Index (Container), then Constraint_Error is propagated. Otherwise, Query_Element calls Process.all with the element at position Index as the argument. Program_Error is propagated if Process.all tampers with the elements of Container. Any exception raised by Process.all is propagated.]} @begin{Reason} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The tamper with the elements check is intended to prevent the Element parameter of Process from being modified or deleted outside of Process. The check prevent data loss (if Element_Type is passed by copy) or erroneous execution (if Element_Type is an unconstrained type in an indefinite container).]} @end{Reason} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Query_Element (Position : @key{in} Cursor; Process : @key{not null access} @key{procedure} (Element : @key{in} Element_Type));]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element, then Constraint_Error is propagated. Otherwise, Query_Element calls Process.@key{all} with the element designated by Position as the argument. Program_Error is propagated if Process.@key{all} tampers with the elements of Container. Any exception raised by Process.@key{all} is propagated.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Update_Element (Container : @key{in} Vector; Index : @key{in} Index_Type; Process : @key{not null access} @key{procedure} (Element : @key{in out} Element_Type));]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[If Index is not in the range First_Index (Container) .. Last_Index (Container), then Constraint_Error is propagated. Otherwise, Update_Element calls Process.@key{all} with the element at position Index as the argument. Program_Error is propagated if Process.@key{all} tampers with the elements of Container. Any exception raised by Process.@key{all} is propagated.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[If Element_Type is unconstrained and definite, then the Element parameter of Process.@key{all} shall be unconstrained.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This means that the elements cannot be directly allocated from the heap; it must be possible to change the discriminants of the element in place.]} @end{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Trailing],Text=[The element at position Index is not an empty element after successful completion of this operation.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Since reading an empty element is a bounded error, attempting to use this procedure to replace empty elements may fail. Use Replace_Element to do that reliably.]} @end{Ramification} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Update_Element (Position : @key{in} Cursor; Process : @key{not null access} @key{procedure} (Element : @key{in out} Element_Type));]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[If Position equals No_Element, then Constraint_Error is propagated. Otherwise, Update_Element calls Process.@key{all} with the element designated by Position as the argument. Program_Error is propagated if Process.@key{all} tampers with the elements of Container. Any exception raised by Process.@key{all} is propagated.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[If Element_Type is unconstrained and definite, then the Element parameter of Process.@key{all} shall be unconstrained.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Trailing],Text=[The element designated by Position is not an empty element after successful completion of this operation.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Replace_Element (Container : @key{in} Vector; Index : @key{in} Index_Type; By : @key{in} Element_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Index is not in the range First_Index (Container) .. Last_Index (Container), then Constraint_Error is propagated. Otherwise Replace_Element assigns the value By to the element at position Index. Any exception raised during the assignment is propagated. The element at position Index is not an empty element after successful call to Replace_Element.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Replace_Element (Position : @key{in} Cursor; By : @key{in} Element_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element, then Constraint_Error is propagated. Otherwise Replace_Element assigns By to the element designated by Position. Any exception raised during the assignment is propagated. The element at Position is not an empty element after successful call to Replace_Element.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Replace_Element and Update_Element are the only ways that an element can change from empty to non-empty.]} @end{Ramification} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Assign (Target : @key{in out} Vector; Source : @key{in} Vector);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Target denotes the same object as Source, then the operation has no effect. Otherwise, Assign first calls Clear (Target), then Reserve_Capacity (Target, Length (Source)). It then assigns the elements of Source to the corresponding positions in Target, and sets the length of Target to the length of Source. Any exception raised during element assignment is propagated.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Move (Target : @key{in out} Vector; Source : @key{in out} Vector);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Target denotes the same object as Source, then Move has no effect. Otherwise, Move first calls Clear (Target); then, each element from Source is removed from Source and inserted into Target in the original order. The length of Source is 0 after a successful call to Move.]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The idea is that the internal array is removed from Source and moved to Target. (See the @ImplAdviceName for Move). If Capacity (Target) /= 0, the previous internal array may need to be deallocated. We don't mention this explicitly, because it is covered by the "no memory loss" @ImplReqName@;.]} @end{Discussion} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Insert (Container : @key{in out} Vector; Before : @key{in} Extended_Index; New_Item : @key{in} Vector);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[If Before is not in the range First_Index (Container) .. Last_Index (Container) + 1, then Constraint_Error is propagated. If Length(New_Item) is 0, then Insert does nothing. Otherwise, it computes the new length @i as the sum of the current length and Length (New_Item); if the value of Last appropriate for length @i would be greater than Index_Type'Last then Constraint_Error is propagated.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If the current vector capacity is less than or equal to @i, Reserve_Capacity (Container, @i) is called to increase the vector capacity. Then Insert slides the elements in the range Before .. Last_Index (Container) up by Length(New_Item) positions, and then copies the elements of New_Item to the positions starting at Before. Any exception raised during the copying is propagated.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Moving the elements does not necessarily involve copying. Similarly, since Reserve_Capacity does not require the copying of elements, it does not need to be explicitly called (the implementation can combine the operations if it wishes to).]} @end{Ramification} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Insert (Container : @key{in out} Vector; Before : @key{in} Cursor; New_Item : @key{in} Vector);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Before is not No_Element, and does not designate an element in Container, then Program_Error is propagated. Otherwise, if Length(New_Item) is 0, then Insert does nothing. If Before is No_Element, then the call is equivalent to Insert (Container, Last_Index (Container) + 1), New_Item); otherwise the call is equivalent to Insert (Container, To_Index (Before), New_Item);]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The check on Before checks that the cursor does not belong to some other Container. This check implies that a reference to the container is included in the cursor value. This wording is not meant to require detection of dangling cursors; such cursors are defined to be invalid, which means that execution is erroneous, and any result is allowed (including not raising an exception).]} @end{Ramification} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Insert (Container : @key{in out} Vector; Before : @key{in} Cursor; New_Item : @key{in} Vector; Position : @key{out} Cursor);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Before is not No_Element, and does not designate an element in Container, then Program_Error is propagated. If Before equals No_Element, then let @i be Last_Index (Container) + 1; otherwise, let @i be To_Index (Before). Insert (Container, @i, New_Item) is called, and then Position is set to To_Cursor (Container, @i).]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The messy wording is needed because Before is invalidated by Insert, and we don't want Position to be invalid after this call. An implementation probably only needs to copy Before to Position.]} @end{Discussion} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Insert (Container : @key{in out} Vector; Before : @key{in} Extended_Index; New_Item : @key{in} Element_Type; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Insert (Container, Before, To_Vector (New_Item, Count));]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Insert (Container : @key{in out} Vector; Before : @key{in} Cursor; New_Item : @key{in} Element_Type; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Insert (Container, Before, To_Vector (New_Item, Count));]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Insert (Container : @key{in out} Vector; Before : @key{in} Cursor; New_Item : @key{in} Element_Type; Position : @key{out} Cursor; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Insert (Container, Before, To_Vector (New_Item, Count), Position);]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Prepend (Container : @key{in out} Vector; New_Item : @key{in} Vector; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Insert (Container, Index_Type'First, New_Item).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Prepend (Container : @key{in out} Vector; New_Item : @key{in} Element_Type; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Insert (Container, Index_Type'First, New_Item, Count).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Append (Container : @key{in out} Vector; New_Item : @key{in} Vector);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Insert (Container, Last_Index (Container) + 1, New_Item).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Append (Container : @key{in out} Vector; New_Item : @key{in} Element_Type; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Insert (Container, Last_Index (Container) + 1, New_Item, Count).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Insert_Space (Container : @key{in out} Vector; Before : @key{in} Extended_Index; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[If Before is not in the range First_Index (Container) .. Last_Index (Container) + 1, then Constraint_Error is propagated. If Count is 0, then Insert_Space does nothing. Otherwise, it computes the new length @i as the sum of the current length and Count; if the value of Last appropriate for length @i would be greater than Index_Type'Last then Constraint_Error is propagated.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If the current vector capacity is less than or equal to @i, Reserve_Capacity (Container, @i) is called to increase the vector capacity. Then Insert_Space slides the elements in the range Before .. Last_Index (Container) up by Count positions, and then inserts empty elements in the positions starting at Before.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Insert_Space (Container : @key{in out} Vector; Before : @key{in} Cursor; Position : @key{out} Cursor; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Before is not No_Element, and does not designate an element in Container, then Program_Error is propagated. If Before equals No_Element, then let @i be Last_Index (Container) + 1; otherwise, let @i be To_Index (Before). Insert_Space (Container, @i, Count) is called, and then Position is set to To_Cursor (Container, @i).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Set_Length (Container : @key{in out} Vector; Length : @key{in} Count_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Length is larger than the capacity of Container, Set_Length calls Reserve_Capacity (Container, Length), then sets the length of the Container to Length. If Length is greater than the original length of Container, empty elements are added to Container; otherwise elements are removed from Container.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[No elements are moved by this operation; any new empty elements are added at the end. This follows from the rules that a cursor continues to designate the same element unless the routine is defined to make the cursor ambiguous or invalid; this operation does not do that.]} @end{Ramification} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Delete (Container : @key{in out} Vector; Index : @key{in} Extended_Index; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Index is not in the range First_Index (Container) .. Last_Index (Container) + 1, then Constraint_Error is propagated. If Count is 0, Delete has no effect. Otherwise Delete slides the elements (if any) starting at position Index + Count down to Index. Any exception raised during element assignment is propagated.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[If Index + Count >= Last_Index(Container), this effectively truncates the vector (setting Last_Index to Index @en 1 and consequently sets Length to Index @en Index_Type'First).]} @end{Ramification} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Delete (Container : @key{in out} Vector; Position : @key{in out} Cursor; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element, then Constraint_Error is propagated. If Position does not designate an element in Container, then Program_Error is propagated. Otherwise, Delete (Container, To_Index (Position), Count) is called.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Delete_First (Container : @key{in out} Vector; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Delete (Container, Index_Type'First, Count).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Delete_Last (Container : @key{in out} Vector; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Length (Container) <= Count then Delete_Last is equivalent to Clear (Container). Otherwise it is equivalent to Delete (Container, Index_Type'Val(Index_Type'Pos(Last_Index(Container)) @en Count + 1), Count).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} First_Index (Container : Vector) @key{return} Index_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns the value Index_Type'First.]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[We'd rather call this @lquotes@;First@rquotes@;, but then calling most routines in here with First (Some_Vect) would be ambiguous.]} @end{Discussion} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} First (Container : Vector) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Container is empty, First returns No_Element. Otherwise, it returns a cursor that designates the first element in Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} First_Element (Container : Vector) @key{return} Element_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Element (Container, First_Index (Container)).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Last_Index (Container : Vector) @key{return} Extended_Index;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Container is empty, Last_Index returns No_Index. Otherwise, it returns the position of the last element in Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Last (Container : Vector) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Container is empty, Last returns No_Element. Otherwise, it returns a cursor that designates the last element in Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Last_Element (Container : Vector) @key{return} Element_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Element (Container, Last_Index (Container)).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Swap (Container : @key{in} Vector; I, J : @key{in} Index_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If I or J is not in the range First_Index (Container) .. Last_Index (Container), then Constraint_Error is propagated. Otherwise, Swap exchanges the values of the elements at positions I and J.]} @begin{Honest} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The implementation is not required to actually copy the elements if it can do the swap some other way. But it is allowed to copy the elements if needed.]} @end{Honest} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Swap (I, J : @key{in} Cursor);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If either I or J is No_Element, then Constraint_Error is propagated. If I and J designate elements in different containers, then Program_Error is propagated. Otherwise Swap exchanges the values of the elements designated by I and J.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[After a call to Swap, I designates the element value previously designated by J, and J designates the element value previously designated by I. The cursors do not become ambiguous from this operation.]} @end{Ramification} @begin{Honest} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The implementation is not required to actually copy the elements if it can do the swap some other way. But it is allowed to copy the elements if needed.]} @end{Honest} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Is_Sorted (Container : Vector) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns True if the elements are sorted smallest first as determined by the generic formal "<" operator; otherwise, Is_Sorted returns False. Any exception raised during evaluation of "<" is propagated.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Sort (Container : @key{in out} Vector);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Reorders the elements of Container such that the elements are sorted smallest first as determined by the generic formal "<" operator provided. Any exception raised during evaluation of "<" is propagated.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This implies swapping the elements, usually including an intermediate copy. This means that the elements will usually be copied. (As with Swap, if the implementation can do this some other way, it is allowed to.) Since the elements are non-limited, this usually will not be a problem. Note that there is @ImplAdviceName below that the implementation should use a sort that minimizes copying of elements.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The sort is not required to be stable (and the fast algorithm required will not be stable). If a stable sort is needed, the user can include the original location of the element as an extra "sort key". We considered requiring the implementation to do that, but it is mostly extra overhead -- usually there is something already in the element that provides the needed stability.]} @end{Ramification} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Merge (Target : @key{in out} Vector; Source : @key{in out} Vector);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Merge removes elements from Source and inserts them into Target; afterwards, Target contains the union of the elements that were initially in Source and Target; Source is left empty. If Target and Source are initially sorted smallest first, then Target is ordered smallest first as determined by the generic formal "<" operator; otherwise, the order of elements in Target is unspecified. Any exception raised during evaluation of "<" is propagated.]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[It is a bounded error if either of the vectors is unsorted, see below. The bounded error can be recovered by sorting Target after the merge call, or the vectors can be pretested with Is_Sorted.]} @end{Discussion} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The Merge operation will usually require copying almost all of the elements. One implementation strategy would be to extend Target to the appropriate length, then copying elements from the back of the vectors working towards the front. An alternative approach would be to allocate a new internal data array of the appropriate length, copy the elements into it in an appropriate order, and then replacing the data array in Target with the temporary.]} @end{ImplNote} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Find_Index (Container : Vector; Item : Element_Type; Index : Index_Type := Index_Type'First) @key{return} Extended_Index;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Searches the elements of Container for an element equal to Item (in the sense of the generic formal equality operator). The search starts at position Index and proceeds towards Last_Index (Container). If no equal element is found, then Find_Index returns No_Index. Otherwise, it returns the index of the first equal element encountered.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Find (Container : Vector; Item : Element_Type; Position : Cursor := No_Element) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position is not No_Element, and does not designate an element in Container, then Program_Error is propagated. Otherwise Find searches the elements of Container for an element equal to Item (in the sense of the generic formal equality operator). The search starts at the first element if Cursor equals No_Element, and at the element designated by Cursor otherwise. It proceeds towards the last element of Container. If no equal element is found, then Find returns No_Cursor. Otherwise, it returns a cursor designating the first equal element encountered.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Reverse_Find_Index (Container : Vector; Item : Element_Type; Index : Index_Type := Index_Type'Last) @key{return} Extended_Index;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Searches the elements of Container for an element equal to Item (in the sense of the generic formal equality operator). The search starts at position Index or, if Index is greater than Last_Index (Container), at position Last_Index (Container). It proceeds towards First_Index (Container). If no equal element is found, then Reverse_Find_Index returns No_Index. Otherwise, it returns the index of the first equal element encountered.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Reverse_Find (Container : Vector; Item : Element_Type; Position : Cursor := No_Element) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position is not No_Element, and does not designate an element in Container, then Program_Error is propagated. Otherwise Reverse_Find searches the elements of Container for an element equal to Item (in the sense of the generic formal equality operator). The search starts at the last element if Cursor equals No_Element, and at the element designated by Cursor otherwise. It proceeds towards the first element of Container. If no equal element is found, then Reverse_Find returns No_Cursor. Otherwise, it returns a cursor designating the first equal element encountered.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Contains (Container : Vector; Item : Element_Type) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Has_Element (Find (Container, Item)).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Next (Position : Cursor) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element or designates the last element of the container, then Next returns the value No_Element. Otherwise, returns a cursor that designates the element with index To_Index (Position) + 1 in the same vector as Position.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Previous (Position : Cursor) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element or designates the first element of the container, then Previous returns the value No_Element. Otherwise, returns a cursor that designates the element with index (To_Index (Position) @en 1) in the same vector as Position.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Next (Position : @key{in out} Cursor);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Position := Next (Position).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Previous (Position : @key{in out} Cursor);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Position := Previous (Position).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Has_Element (Position : Cursor) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns True if Position designates an element, and returns False otherwise.]} @begin{Honest} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This function may not detect cursors that designate deleted elements; such cursors are invalid (see below) and the result of calling Has_Element with an invalid cursor is unspecified (but not erroneous).]} @end{Honest} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Iterate (Container : @key{in} Vector; Process : @key{not null access} @key{procedure} (Position : @key{in} Cursor));]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Invokes Process.@key{all} with a cursor that designates each element in Container, in index order. Program_Error is propagated if Process.@key{all} tampers with the cursors of Container. Any exception raised by Process is propagated.]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The purpose of the tamper with cursors check is to prevent erroneous execution from the Position parameter of Process.all becoming invalid. This check takes place when the operations that tamper with the cursors of the container are called. The check cannot be made later (say in the body of Iterate), because that could cause the Position cursor to be invalid and potentially cause execution to become erroneous -- defeating the purpose of the check.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ There is no check needed if an attempt is made to insert or delete nothing (that is, Count = 0 or Length(Item) = 0).]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The check is easy to implement: each container needs a counter. The counter is incremented when Iterate is called, and decremented when Iterate completes. If the counter is nonzero when an operation that inserts or deletes is called, Finalize is called, or one of the other operations in the list occurs, Program_Error is raised.]} @end{Discussion} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Reverse_Iterate (Container : @key{in} Vector; Process : @key{not null access} @key{procedure} (Position : @key{in} Cursor));]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Iterates over the nodes in Container as per Iterate, except that elements are traversed in reverse index order.]} @end{DescribeCode} @end{StaticSem} @begin{Bounded} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@PDefn2{Term=(bounded error),Sec=(cause)} Reading the value of an empty element by calling Element, Query_Element, Update_Element, Swap, Is_Sorted, Sort, Merge, "=", Find, or Reverse_Find is a bounded error. The implementation may treat the element as having any valid value of the element type, or raise Constraint_Error or Program_Error before modifying the vector.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[For instance, a default initialized element could be returned. Or some previous value of an element. But returning random junk is not allowed if the type has default initial value(s).]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Assignment and streaming of empty elements are @b bounded errors. This is consistent with regular composite types, for which assignment and streaming of uninitialized components do not cause a bounded error, but reading the uninitialized component does cause a bounded error.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[There are other operations which are defined in terms of the operations listed above.]} @end{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@PDefn2{Term=(bounded error),Sec=(cause)} Calling Merge in an instance of Generic_Sorting with either Source or Target not ordered smallest first using the provided generic formal "<" operator is a bounded error. Either Program_Error is raised after Target is updated as described for Merge, or the operation works as defined.]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[ @Defn2{Term=[ambiguous cursor],Sec=[of a vector]} @Defn2{Term=[cursor],Sec=[ambiguous]} A Cursor value is @i{ambiguous} if any of the following have occurred since it was created:]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Insert, Insert_Space, or Delete has been called on the vector that contains the element the cursor designates with an index value (or a cursor designating an element at such an index value) less than or equal to the index value of the element designated by the cursor; or]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The vector that contains the element it designates has been passed to the Sort or Merge procedures of an instance of Generic_Sorting.]} @end{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[@PDefn2{Term=(bounded error),Sec=(cause)} It is a bounded error to call any subprogram other than "=" or Has_Element declared in Containers.Vectors with an ambiguous (but not invalid, see below) cursor parameter. Possible results are:]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The cursor may be treated as if it was No_Element;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The cursor may designate some element in the vector (but not necessarily the element that it originally designated);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Constraint_Error may be raised; or]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Program_Error may be raised.]} @end{Itemize} @begin{Reason} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Cursors are made ambiguous if an Insert or Delete occurs that moves the elements in the internal array including the designated ones. After such an operation, the cursor probably still designates an element (although it might not after a deletion), but it is a @i element. That violates the definition of cursor @em it designates a particular element.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[For "=" or Has_Element, the cursor works normally (it would not be No_Element). We don't want to trigger an exception simply for comparing a bad cursor.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[While it is possible to check for or prevent these cases, in many cases the overhead necessary to make the check (or prevent the problems) is substantial in time or space.]} @end{Reason} @end{Bounded} @begin{Erron} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[ A Cursor value is @i{invalid} if any of the following have occurred since it was created:@Defn2{Term=[invalid cursor],Sec=[of a vector]} @PDefn2{Term=[cursor],Sec=[invalid]}]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The vector that contains the element it designates has been finalized;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The vector that contains the element it designates has been used as the Source or Target of a call to Move; or]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The element it designates has been deleted.]} @end{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The result of "=" or Has_Element is unspecified if it is called with an invalid cursor parameter.@PDefn{unspecified} Execution is erroneous if any other subprogram declared in Containers.Vectors is called with an invalid cursor parameter.@PDefn2{Term=(erroneous execution), Sec=(cause)}]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The list above (combined with the bounded error cases) is intended to be exhaustive. In other cases, a cursor value continues to designate its original element. For instance, cursor values survive the appending of new elements.]} @end{Discussion} @end{Erron} @begin{ImplReq} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[No storage associated with a vector object shall be lost upon assignment or scope exit.]} @end{ImplReq} @begin{ImplAdvice} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Containers.Vectors should be implemented similarly to an array. In particular, if the length of a vector is @i{N}, then]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[the worst-case time complexity of Append with Count=1 and Element should be O(log @i{N}); and]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[The worst-case time complexity of Append with Count = 1 and Element for Containers.Vector should be O(log @i{N}).]}]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[the worst-case time complexity of Prepend with Count=1 and Delete_First with Count=1 should be O(@i{N} log @i{N}).]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[The worst-case time complexity of Prepend with Count = 1 and Delete_First with Count=1 for Containers.Vectors should be O(@i{N} log @i{N}).]}]} @end{Itemize} @begin{Reason} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[We do not mean to overly constrain implementation strategies here. However, it is important for portability that the performance of large containers has roughly the same factors on different implementations. If a program is moved to an implementation that takes O(@i{N}) time to access elements, that program could be unusable when the vectors are large. We allow O(log @i{N}) access because the proportionality constant and caching effects are likely to be larger than the log factor, and we don't want to discourage innovative implementations.]} @end{Reason} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The worst-case time complexity of a call on procedure Sort of an instantiation of Containers.Vectors.Generic_Sorting should be O(@i{N}**2), and the average time complexity should be better than O(@i{N}**2).]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[The worst-case time complexity of a call on procedure Sort of an instantiation of Containers.Vectors.Generic_Sorting should be O(@i{N}**2), and the average time complexity should be better than O(@i{N}**2).]}]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[In other words, we're requiring the use of a better than O(@i{N}**2) sorting algorithm, such as Quicksort. No bubble sorts allowed!]} @end{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Containers.Vectors.Generic_Sorting.Sort and Containers.Vectors.Generic_Sorting.Merge should minimize copying of elements.]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[Containers.Vectors.Generic_Sorting.Sort and Containers.Vectors.Generic_Sorting.Merge should minimize copying of elements.]}]} @begin{Honest} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[We do not mean @lquotes@;absolutely minimize@rquotes here; we're not intending to require a single copy for each element. Rather, we want to suggest that the sorting algorithm chosen is one that does not copy items unnecessarily. Bubble sort would not meet this advice, for instance.]} @end{Honest} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Move should not copy elements, and should minimize copying of internal data structures.]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[Containers.Vectors.Move should not copy elements, and should minimize copying of internal data structures.]}]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Usually that can be accomplished simply by moving the pointer(s) to the internal data structures from the Source vector to the Target vector.]} @end{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[If an exception is propagated from a vector operation, no storage should be lost, nor any elements removed from a vector unless specified by the operation.]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[If an exception is propagated from a vector operation, no storage should be lost, nor any elements removed from a vector unless specified by the operation.]}]} @begin{Reason} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This is important so that programs can recover from errors. But we don't want to require heroic efforts, so we just require documentation of cases where this can't be accomplished.]} @end{Reason} @end{ImplAdvice} @begin{Notes} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[All elements of a vector occupy locations in the internal array. If a sparse container is required, a Hashed_Map should be used rather than a vector.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[If Index_Type'Base'First = Index_Type'First an instantiation of Ada.Containers.Vectors will raise Constraint_Error. A value below Index_Type'First is required so that an empty vector has a meaningful value of Last_Index.]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This property is the main reason why only integer types (as opposed to any discrete type) are allowed as the index type of a vector. An enumeration or modular type would require a subtype in order to meet this requirement.]} @end{Discussion} @end{Notes} @begin{Extend95} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn{extensions to Ada 95} The package Ada.Containers.Vectors is new.]} @end{Extend95} @LabeledAddedSubclause{Version=[2], Name=[The Package Containers.Doubly_Linked_Lists]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The language-defined generic package Containers.Doubly_Linked_Lists provides private types List and Cursor, and a set of operations for each type. A list container is optimized for insertion and deletion at any position. @Defn{list container}@Defn2{Term=[container],Sec=[list]}]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn2{Term=[node],Sec=[of a list]}A doubly-linked list container object manages a linked list of internal @i{nodes}, each of which contains an element and pointers to the next (successor) and previous (predecessor) internal nodes. A cursor designates a particular node within a list (and by extension the element contained in that node). A cursor keeps designating the same node (and element) as long as the node is part of the container, even if the node is moved in the container.]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The @i{length} of a list is the number of elements it contains.@Defn2{Term=[length],Sec=(of a list container)}]} @begin{StaticSem} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],KeepNext=[T],Type=[Leading],Text=[The generic library package Containers.Doubly_Linked_Lists has the following declaration:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{generic} @key{type} Element_Type @key{is private}; @key{with function} "=" (Left, Right : Element_Type) @key{return} Boolean @key{is} <>; @key{package} Ada.Containers.Doubly_Linked_Lists @key{is}@ChildUnit{Parent=[Ada.Containers],Child=[Doubly_@!Linked_@!Lists]} @key{pragma} Preelaborate(Doubly_Linked_Lists);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{type} @AdaTypeDefn{List} @key{is tagged private}; @key{pragma} Preelaborable_Initialization(List);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{type} @AdaTypeDefn{Cursor} @key{is private}; @key{pragma} Preelaborable_Initialization(Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @AdaDefn{Empty_List} : @key{constant} List;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @AdaDefn{No_Element} : @key{constant} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "=" (Left, Right : List) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Length} (Container : List) @key{return} Count_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Is_Empty} (Container : List) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Clear} (Container : @key{in out} List);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Element} (Position : Cursor) @key{return} Element_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Query_Element} (Position : @key{in} Cursor; Process : @key{not null access procedure} (Element : @key{in} Element_Type));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Update_Element} (Position : @key{in} Cursor; Process : @key{not null access procedure} (Element : @key{in out} Element_Type));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Replace_Element} (Position : @key{in} Cursor; By : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Move} (Target : @key{in out} List; Source : @key{in out} List);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Prepend} (Container : @key{in out} List; New_Item : @key{in} Element_Type; Count : @key{in} Count_Type := 1);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Append} (Container : @key{in out} List; New_Item : @key{in} Element_Type; Count : @key{in} Count_Type := 1);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert} (Container : @key{in out} List; Before : @key{in} Cursor; New_Item : @key{in} Element_Type; Count : @key{in} Count_Type := 1);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert} (Container : @key{in out} List; Before : @key{in} Cursor; New_Item : @key{in} Element_Type; Position : @key{out} Cursor; Count : @key{in} Count_Type := 1);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert} (Container : @key{in out} List; Before : @key{in} Cursor; Position : @key{out} Cursor; Count : @key{in} Count_Type := 1);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete} (Container : @key{in out} List; Position : @key{in out} Cursor; Count : @key{in} Count_Type := 1);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete_First} (Container : @key{in out} List; Count : @key{in} Count_Type := 1);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete_Last} (Container : @key{in out} List; Count : @key{in} Count_Type := 1);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{generic} @key{with function} "<" (Left, Right : Element_Type) @key{return} Boolean is <>; @key{package} @AdaDefn{Generic_Sorting} @key{is}]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Is_Sorted} (Container : List) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Sort} (Container : @key{in out} List);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Merge} (Target : @key{in out} List; Source : @key{in out} List);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{end} Generic_Sorting;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Reverse_List} (Container : @key{in out} List);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Swap} (I, J : @key{in} Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Swap_Links} (Container : @key{in out} List; I, J : @key{in} Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Splice} (Target : @key{in out} List; Before : @key{in} Cursor; Source : @key{in out} List);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Splice} (Target : @key{in out} List; Before : @key{in} Cursor; Source : @key{in out} List; Position : @key{in out} Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Splice} (Container: @key{in out} List; Before : @key{in} Cursor; Position : @key{in out} Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{First} (Container : List) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{First_Element} (Container : List) @key{return} Element_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Last} (Container : List) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Last_Element} (Container : List) @key{return} Element_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Contains} (Container : List; Item : Element_Type) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Find} (Container : List; Item : Element_Type; Position : Cursor := No_Element) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Reverse_Find} (Container : List; Item : Element_Type; Position : Cursor := No_Element) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Next} (Position : Cursor) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Previous} (Position : Cursor) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Next} (Position : @key{in out} Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Previous} (Position : @key{in out} Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Has_Element} (Position : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Iterate} (Container : @key{in} List; Process : @key{not null access procedure} (Position : @key{in} Cursor));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Reverse_Iterate} (Container : @key{in} List; Process : @key{not null access procedure} (Position : @key{in} Cursor));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{private}]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ ... -- @RI[not specified by the language]]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{end} Ada.Containers.Doubly_Linked_Lists;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The type List is used to represent lists. The type List needs finalization (see @RefSecNum{User-Defined Assignment and Finalization}).]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Empty_List represents the empty List object. It has a length of 0. If an object of type List is not otherwise initialized, it is initialized to the same value as Empty_List.]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[No_Element represents a cursor that designates no element. If an object of type Cursor is not otherwise initialized, it is initialized to the same value as No_Element.]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[@Defn2{Term=[tamper with cursors],Sec=[of a list]} Some operations are assumed to work on a constant set of elements. For such an operation, a subprogram is said to @i{tamper with cursors} of a list object @i if:]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it inserts or deletes elements of @i, that is, it calls the Insert, Clear, Delete, or Delete_Last procedures with @i as a parameter; or]} @begin{Honest} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Operations which are defined to be equivalent to a call on one of these operations also are included. Similarly, operations which call one of these as part of their definition are included.]} @end{Honest} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it reorders the elements of @i, that is, it calls the Splice, Swap_Links, or Reverse_List procedures or the Sort or Merge procedures of an instance of Generic_Sorting with @i as a parameter; or]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it finalizes @i; or]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it calls the Move procedure with @i as a parameter.]} @end{Itemize} @begin{Reason} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Swap copies elements rather than reordering them, so it doesn't tamper with cursors.]} @end{Reason} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[@Defn2{Term=[tamper with elements],Sec=[of a list]} Some operations are assumed to not replace elements. For such an operation, a subprogram is said to @i{tamper with elements} of a list object @i if:]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it tampers with cursors of @i; or]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it replaces one or more elements of @i, that is, it calls the Replace_Element or Swap procedures with @i as a parameter.]} @begin{Reason} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Complete replacement of an element can cause its memory to be deallocated while another operation is holding onto a reference to it. That can't be allowed. However, a simple modification of (part of) an element is not a problem, so Update_Element does not cause a problem.]} @end{Reason} @end{Itemize} @begin{DescribeCode} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} "=" (Left, Right : List) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Left and Right denote the same list object, then the function returns True. If Left and Right have different lengths, then the function returns False. Otherwise, it compares each element in Left to the corresponding element in Right using the generic formal equality operator; if element equality returns False, then the function returns False. If the function has not returned a result after checking all of the elements, it returns True. Any exception raised during evaluation of element equality is propagated.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Length (Container : List) @key{return} Count_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns the number of elements in Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Is_Empty (Container : List) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Length (Container) = 0.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Clear (Container : @key{in out} List);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Removes all the elements from Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Element (Position : Cursor) @key{return} Element_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element, then Constraint_Error is propagated. Otherwise, Element returns the element designated by Position.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Query_Element (Position : @key{in} Cursor; Process : @key{not null access procedure} (Element : @key{in} Element_Type));]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element, then Constraint_Error is propagated. Otherwise, Query_Element calls Process.@key{all} with the element on node designated by Position as the argument. Program_Error is propagated if Process.@key{all} tampers with the elements of Container. Any exception raised by Process.@key{all} is propagated.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Update_Element (Position : @key{in} Cursor; Process : @key{not null access procedure} (Element : @key{in out} Element_Type));]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[If Position equals No_Element, then Constraint_Error is propagated. Otherwise, Update_Element calls Process.@key{all} with the element on node designated by Position as the argument. Program_Error is propagated if Process.@key{all} tampers with the elements of Container. Any exceptions raised by Process.@key{all} are propagated.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Element_Type is unconstrained and definite, then the Element parameter of Process.@key{all} shall be unconstrained.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This means that the elements cannot be directly allocated from the heap; it must be possible to change the discriminants of the element in place.]} @end{Ramification} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Replace_Element (Position : Cursor; By : Element_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element, then Constraint_Error is propagated. Otherwise Replace_Element assigns the value By to the element designated by Position.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Move (Target : @key{in out} List; Source : @key{in out} List);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Target denotes the same object as Source, then Move has no effect. Otherwise, Move first calls Clear (Target). Then, the nodes in Source are moved to Target (in the original order). The length of Target is set to the length of Source, and the length of Source is set to 0.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Prepend (Container : @key{in out} List; New_Item : @key{in} Element_Type; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Insert (Container, First (Container), New_Item, Count).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Append (Container : @key{in out} List; New_Item : @key{in} Element_Type; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Insert (Container, No_Element, New_Item, Count).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Insert (Container : @key{in out} List; Before : @key{in} Cursor; New_Item : @key{in} Element_Type; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Before is not No_Element, and does not designate an element in Target, then Program_Error is propagated. Otherwise, Insert inserts Count copies of New_Item prior to the element designated by Before. If Before equals No_Element, the new elements are inserted after the last node (if any). Any exception raised during allocation of internal storage is propagated, and Container is not modified.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The check on Before checks that the cursor does not belong to some other Container. This check implies that a reference to the container is included in the cursor value. This wording is not meant to require detection of dangling cursors; such cursors are defined to be invalid, which means that execution is erroneous, and any result is allowed (including not raising an exception).]} @end{Ramification} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Insert (Container : @key{in out} List; Before : @key{in} Cursor; New_Item : @key{in} Element_Type; Position : @key{out} Cursor; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Before is not No_Element, and does not designate an element in Container, then Program_Error is propagated. Otherwise, Insert allocates Count copies of New_Item, and inserts them prior to the element designated by Before. If Before equals No_Element, the new elements are inserted after the last element (if any). Position designates the first newly-inserted element. Any exception raised during allocation of internal storage is propagated, and Container is not modified.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Insert (Container : @key{in out} List; Before : @key{in} Cursor; Position : @key{out} Cursor; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Before is not No_Element, and does not designate an element in Container, then Program_Error is propagated. Otherwise, Insert inserts Count new elements prior to the element designated by Before. If Before equals No_Element, the new elements are inserted after the last node (if any). The new elements are initialized with any implicit initial value for any part (as for an @nt{object_declaration} with no initialization expression @em see 3.3.1). Any exception raised during allocation of internal storage is propagated, and Container is not modified.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Delete (Container : @key{in out} List; Position : @key{in out} Cursor; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element, then Constraint_Error is propagated. If Position does not designate an element in Container, then Program_Error is propagated. Otherwise Delete removes (from Container) Count elements starting at the element designated by Position (or all of the elements starting at Position if there are fewer than Count elements starting at Position).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Delete_First (Container : @key{in out} List; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Delete (Container, First (Container), Count).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Delete_Last (Container : @key{in out} List; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Length (Container) <= Count then Delete_Last is equivalent to Clear (Container). Otherwise it removes the last Count nodes from Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Is_Sorted (Container : List) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns True if the elements are sorted smallest first as determined by the generic formal "<" operator; otherwise, Is_Sorted returns False. Any exception raised during evaluation of "<" is propagated.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Sort (Container : @key{in out} List);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Reorders the nodes of Container such that the elements are sorted smallest first as determined by the generic formal "<" operator provided. The sort is stable. Any exception raised during evaluation of "<" is propagated.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Unlike array sorts, we do require stable sorts here. That's because algorithms in the merge sort family (as described by Knuth) can be both fast and stable. Such sorts use the extra memory as offered by the links to provide better performance.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Note that list sorts never copy elements; it is the nodes, not the elements, that are reordered.]} @end{Ramification} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Merge (Target : @key{in out} List; Source : @key{in out} List);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Merge removes elements from Source and inserts them into Target; afterwards, Target contains the union of the elements that were initially in Source and Target; Source is left empty. If Target and Source are initially sorted smallest first, then Target is ordered smallest first as determined by the generic formal "<" operator; otherwise, the order of elements in Target is unspecified. Any exception raised during evaluation of "<" is propagated.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[It is a bounded error if either of the lists is unsorted, see below. The bounded error can be recovered by sorting Target after the merge call, or the lists can be pretested with Is_Sorted.]} @end{Ramification} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Reverse_List (Container : @key{in out} List);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Reorders the elements of Container in reverse order.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Swap (I, J : @key{in} Cursor);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If either I or J is No_Element, then Constraint_Error is propagated. If I and J designate elements in different containers, then Program_Error is propagated. Otherwise Swap exchanges the values of the elements designated by I and J.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[After a call to Swap, I designates the element value previously designated by J, and J designates the element value previously designated by I. The cursors do not become ambiguous from this operation.]} @end{Ramification} @begin{Honest} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The implementation is not required to actually copy the elements if it can do the swap some other way. But it is allowed to copy the elements if needed.]} @end{Honest} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Swap_Links (Container : @key{in out} List; I, J : @key{in} Cursor);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If either I or J is No_Element, then Constraint_Error is propagated. If I or J do not designate an element in Container, then Program_Error is propagated. Otherwise, Swap_Links exchanges the nodes designated by I and J.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Unlike Swap, this exchanges the nodes, not the elements. No copying is performed. I and J designate the same elements after this call as they did before it. This operation can provide better performance than Swap if the element size is large.]} @end{Ramification} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Splice (Target : @key{in out} List; Before : @key{in} Cursor; Source : @key{in out} List);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Before is not No_Element, and does not designate an element in Target, then Program_Error is propagated. Otherwise, if Source denotes the same object as Target, the operation has no effect. Otherwise, Splice reorders elements such that they are removed from Source and moved to Target, immediately prior to Before. If Before equals No_Element, the nodes of Source are spliced after the last node of Target. The length of Target is incremented by the number of nodes in Source, and the length of Source is set to 0.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Splice (Target : @key{in out} List; Before : @key{in} Cursor; Source : @key{in out} List; Position : @key{in out} Cursor);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position is No_Element then Constraint_Error is propagated. If Before does not equal No_Element, and does not designate an element in Target, then Program_Error is propagated. If Position does not equal No_Element, and does not designate a node in Source, then Program_Error is propagated. If Source denotes the same object as Target, then there is no effect if Position equals Before, else the element designated by Position is moved immediately prior to Before, or, if Before equals No_Element, after the last element. Otherwise the element designated by Position is removed from Source and moved to Target, immediately prior to Before, or, if Before equals No_Element, after the last element of Target. The length of Target is incremented, the length of Source is decremented, and Position is updated to represent an element in Target.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[If Source is the same as Target, and Position = Before, or Next(Position} = Before, Splice has no effect, as the element does not have to move to meet the postcondition.]} @end{Ramification} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Splice (Container: @key{in out} List; Before : @key{in} Cursor; Position : @key{in out} Cursor);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Splice (Target => Container, Before => Before, Source => Container, Position => Position);]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} First (Container : List) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Container is empty, First returns the value No_Element. Otherwise it returns a cursor that designates the first node in Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} First_Element (Container : List) @key{return} Element_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Element (First (Container)).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Last (Container : List) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Container is empty, Last returns the value No_Element. Otherwise it returns a cursor that designates the last node in Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Last_Element (Container : List) @key{return} Element_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Element (Last (Container)).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Contains (Container : List; Item : Element_Type) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Find (Container, Item) /= No_Element.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Find (Container : List; Item : Element_Type; Position : Cursor := No_Element) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position is not No_Element, and does not designate an element in Container, then Program_Error is propagated. Find searches the elements of Container for an element equal to Item (in the sense of the generic formal equality operator). The search starts at the element designated by Position, or at the first element if Position equals No_Element. It proceeds towards Last (Container). If no equal element is found, then Find returns No_Element. Otherwise, it returns a cursor designating the first equal element encountered.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Reverse_Find (Container : List; Item : Element_Type; Position : Cursor := No_Element) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position is not No_Element, and does not designate an element in Container, then Program_Error is propagated. Find searches the elements of Container for an element equal to Item (in the sense of the generic formal equality operator). The search starts at the element designated by Position, or at the lastelement if Position equals No_Element. It proceeds towards First (Container). If no equal element is found, then Reverse_Find returns No_Element. Otherwise, it returns a cursor designating the first equal element encountered.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Next (Position : Cursor) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element or designates the last element of the container, then Next returns the value No_Element. Otherwise, it returns a cursor that designates the successor of the element designated by Position.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Previous (Position : Cursor) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element or designates the first element of the container, then Previous returns the value No_Element. Otherwise, it returns a cursor that designates the predecessor of the element designated by Position.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Next (Position : @key{in out} Cursor);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Position := Next (Position).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Previous (Position : @key{in out} Cursor);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Position := Previous (Position).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Has_Element (Position : Cursor) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns True if Position designates an element, and returns False otherwise.]} @begin{Honest} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This function may not detect cursors that designate deleted elements; such cursors are invalid (see below) and the result of Has_Element for an invalid cursor is unspecified (but not erroneous).]} @end{Honest} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Iterate (Container : @key{in} List; Process : @key{not null access procedure} (Position : @key{in} Cursor));]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Iterate calls Process.@key{all} with a cursor that designates each node in Container, starting with the first node and moving the cursor as per the Next function. Program_Error is propagated if Process.@key{all} tampers with the cursors of Container. Any exception raised by Process.@key{all} is propagated.]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The purpose of the tamper with cursors check is to prevent erroneous execution from the Position parameter of Process.all becoming invalid. This check takes place when the operations that tamper with the cursors of the container are called. The check cannot be made later (say in the body of Iterate), because that could cause the Position cursor to be invalid and potentially cause execution to become erroneous -- defeating the purpose of the check.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[See Iterate for vectors (@RefSecNum{The Package Containers.Vectors}) for a suggested implementation of the check.]} @end{ImplNote} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Reverse_Iterate (Container : @key{in} List; Process : @key{not null access procedure} (Position : @key{in} Cursor));]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Iterates over the nodes in Container as per Iterate, except that elements are traversed in reverse order, starting with the last node and moving the cursor as per the Previous function.]} @end{DescribeCode} @end{StaticSem} @begin{Bounded} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@PDefn2{Term=(bounded error),Sec=(cause)} Calling Merge in an instance of Generic_Sorting with either Source or Target not ordered smallest first using the provided generic formal "<" operator is a bounded error. Either Program_Error is raised after Target is updated as described for Merge, or the operation works as defined.]} @end{Bounded} @begin{Erron} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[A Cursor value is @i if any of the following have occurred since it was created:@Defn2{Term=[invalid cursor],Sec=[of a list container]} @PDefn2{Term=[cursor],Sec=[invalid]}]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The list that contains the element it designates has been finalized;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The list that contains the element it designates has been used as the Source or Target of a call to Move; or]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The element it designates has been deleted.]} @end{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The result of "=" or Has_Element is unspecified if it is called with an invalid cursor parameter. Execution is erroneous if any other subprogram declared in Containers.Doubly_Linked_Lists is called with an invalid cursor parameter. @PDefn{unspecified}@PDefn2{Term=(erroneous execution),Sec=(cause)}]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The list above is intended to be exhaustive. In other cases, a cursor value continues to designate its original element. For instance, cursor values survive the insertion and deletion of other nodes.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[While it is possible to check for these cases, in many cases the overhead necessary to make the check is substantial in time or space. Implementations are encouraged to check for as many of these cases as possible and raise Program_Error if detected.]} @end{Discussion} @end{Erron} @begin{ImplReq} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[No storage associated with a doubly-linked List object shall be lost upon assignment or scope exit.]} @end{ImplReq} @begin{ImplAdvice} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Containers.Doubly_Linked_Lists should be implemented similarly to a linked list. In particular, if @i is the length of a list, then the worst-case time complexity of Element, Insert with Count=1, and Delete with Count=1 should be O(log @i).]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[The worst-case time complexity of Element, Insert with Count=1, and Delete with Count=1 for Containers.Doubly_Linked_Lists should be O(log @i).]}]} @begin{Reason} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[We do not mean to overly constrain implementation strategies here. However, it is important for portability that the performance of large containers has roughly the same factors on different implementations. If a program is moved to an implementation that takes O(@i) time to access elements, that program could be unusable when the lists are large. We allow O(log @i) access because the proportionality constant and caching effects are likely to be larger than the log factor, and we don't want to discourage innovative implementations.]} @end{Reason} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The worst-case time complexity of a call on procedure Sort of an instantiation of Containers.Doubly_Linked_Lists.Generic_Sorting should be O(@i**2), and the average time complexity should be better than O(@i**2).]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[a call on procedure Sort of an instantiation of Containers.Doubly_Linked_Lists.Generic_Sorting should have an average time complexity better than O(@i{N}**2) and worst case no worse than O(@i{N}**2).]}]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[In other words, we're requiring the use of a better than O(@i{N}**2) sorting algorithm, such as Quicksort. No bubble sorts allowed!]} @end{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Move should not copy elements, and should minimize copying of internal data structures.]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[Containers.Doubly_Link_Lists.Move should not copy elements, and should minimize copying of internal data structures.]}]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Usually that can be accomplished simply by moving the pointer(s) to the internal data structures from the Source container to the Target container.]} @end{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[If an exception is propagated from a list operation, no storage should be lost, nor any elements removed from a list unless specified by the operation.]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[If an exception is propagated from a list operation, no storage should be lost, nor any elements removed from a list unless specified by the operation.]}]} @begin{Reason} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This is important so that programs can recover from errors. But we don't want to require heroic efforts, so we just require documentation of cases where this can't be accomplished.]} @end{Reason} @end{ImplAdvice} @begin{Notes} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Sorting a list never copies elements, and is a stable sort (equal elements remain in the original order). This is different than sorting an array or vector, which may need to copy elements, and is probably not a stable sort.]} @end{Notes} @begin{Extend95} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn{extensions to Ada 95} The generic package Ada.Containers.Doubly_Linked_Lists is new.]} @end{Extend95} @LabeledAddedSubclause{Version=[2],Name=[Maps]} @begin{Intro} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The language-defined generic packages Containers.Hashed_Maps and Containers.Ordered_Maps provide private types Map and Cursor, and a set of operations for each type. A map container allows an arbitrary type to be used as a key to find the element associated with that key. A hashed map uses a hash function to organize the keys, while an ordered map orders the keys per a specified relation. @Defn{map container}@Defn2{Term=[container],Sec=[map]}]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[This section describes the declarations that are common to both kinds of maps. See @RefSecNum{The Package Containers.Hashed_Maps} for a description of the semantics specific to Containers.Hashed_Maps and @RefSecNum{The Package Containers.Ordered_Maps} for a description of the semantics specific to Containers.Ordered_Maps.]} @end{Intro} @begin{StaticSem} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The type Map is used to represent maps. The type Map needs finalization (see @RefSecNum{User-Defined Assignment and Finalization}).]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn2{Term=[node],Sec=[of a map]}A map contains pairs of keys and elements, called @i{nodes}. Map cursors designate nodes, but also can be thought of as designating an element (the element contained in the node) for consistency with the other containers. There exists an equivalence relation on keys, whose definition is different for hashed maps and ordered maps. A map never contains two or more nodes with equivalent keys. The @i{length} of a map is the number of nodes it contains.@Defn2{Term=[length],Sec=[of a map]}]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn2{Term=[first node],Sec=[of a map]} @Defn2{Term=[last node],Sec=[of a map]} @Defn2{Term=[successor node],Sec=[of a map]}Each nonempty map has two particular nodes called the @i{first node} and the @i{last node} (which may be the same). Each node except for the last node has a @i{successor node}. If there are no other intervening operations, starting with the first node and repeatedly going to the successor node will visit each node in the map exactly once until the last node is reached. The exact definition of these terms is different for hashed maps and ordered maps.]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[ @Defn2{Term=[tamper with cursors],Sec=[of a map]} Some operations are assumed to work on a constant set of elements. For such an operation, a subprogram is said to @i{tamper with cursors} of a map object @i if:]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it inserts or deletes elements of @i, that is, it calls the Insert, Include, Clear, Delete, or Exclude procedures with @i as a parameter; or]} @begin{Honest} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Operations which are defined to be equivalent to a call on one of these operations also are included. Similarly, operations which call one of these as part of their definition are included.]} @end{Honest} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it finalizes @i; or]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it calls the Move procedure with @i as a parameter; or]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it calls one of the operations defined to tamper with the cursors of @i.]} @end{Itemize} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Replace only modifies a key and element rather than rehashing, so it does not tamper with cursors.]} @end{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[ @Defn2{Term=[tamper with elements],Sec=[of a map]} Some operations are assumed to not replace elements. For such an operation, a subprogram is said to @i{tamper with elements} of a map object @i if:]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it tampers with cursors of @i; or]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it replaces one or more elements of @i, that is, it calls the Replace or Replace_Element procedures with @i as a parameter.]} @begin{Reason} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Complete replacement of an element can cause its memory to be deallocated while another operation is holding onto a reference to it. That can't be allowed. However, a simple modification of (part of) an element is not a problem, so Update_Element does not cause a problem.]} @end{Reason} @end{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Empty_Map represents the empty Map object. It has a length of 0. If an object of type Map is not otherwise initialized, it is initialized to the same value as Empty_Map.]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[No_Element represents a cursor that designates no node. If an object of type Cursor is not otherwise initialized, it is initialized to the same value as No_Element.]} @begin{DescribeCode} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} "=" (Left, Right : Map) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[If Left and Right denote the same map object, then the function returns True. If Left and Right have different lengths, then the function returns False. Otherwise, for each key @i in Left, the function returns False if:]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[a key equivalent to @i is not present in Right; or]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[the element associated with @i in Left is not equal to the element associated with @i in Right (using the generic formal equality operator for elements).]} @end{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If the function has not returned a result after checking all of the keys, it returns True. Any exception raised during evaluation of key equivalence or element equality is propagated.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Length (Container : Map) @key{return} Count_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns the number of nodes in Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Is_Empty (Container : Map) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Length (Container) = 0.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Clear (Container : @key{in out} Map);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Removes all the nodes from Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Key (Position : Cursor) @key{return} Key_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element, then Constraint_Error is propagated. Otherwise, Key returns the key component of the node designated by Position.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Element (Position : Cursor) @key{return} Element_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element, then Constraint_Error is propagated. Otherwise, Element returns the element component of the node designated by Position.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Query_Element (Position : @key{in} Cursor; Process : @key{not null access procedure} (Key : @key{in} Key_Type; Element : @key{in} Element_Type));]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element, then Constraint_Error is propagated. Otherwise, Query_Element calls Process.@key{all} with the key and element from the node designated by Position as the arguments. Program_Error is propagated if Process.@key{all} tampers with the elements of Container. Any exceptions raised by Process.@key{all} are propagated.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Update_Element (Position : @key{in} Cursor; Process : @key{not null access procedure} (Key : @key{in} Key_Type; Element : @key{in out} Element_Type));]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element, then Constraint_Error is propagated. Otherwise, Update_Element calls Process.@key{all} with the key and element from the node designated by Position as the arguments. Program_Error is propagated if Process.@key{all} tampers with the elements of Container. Any exceptions raised by Process.@key{all} are propagated.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Trailing],Type=[Trailing],Text=[If Element_Type is unconstrained and definite, then the Element parameter of Process.@key{all} shall be unconstrained.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This means that the elements cannot be directly allocated from the heap; it must be possible to change the discriminants of the element in place.]} @end{Ramification} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Replace_Element (Position : @key{in} Cursor; By : @key{in} Element_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element, then Constraint_Error is propagated. Otherwise Replace_Element assigns By to the element of the node designated by Position.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Move (Target : @key{in out} Map; Source : @key{in out} Map);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Target denotes the same object as Source, then Move has no effect. Otherwise, Move first calls Clear (Target). Then, each node from Source is removed from Source and inserted into Target. The length of Source is 0 after a successful call to Move.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Insert (Container : @key{in out} Map; Key : @key{in} Key_Type; New_Item : @key{in} Element_Type; Position : @key{out} Cursor; Inserted : @key{out} Boolean);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Insert checks if a node with a key equivalent to Key is already present in Container. If a match is found, Inserted is set to False and Position designates the element with the matching key. Otherwise, Insert allocates a new node, initializes it to Key and New_Item, and adds it to Container; Inserted is set to True and Position designates the newly-inserted node. Any exception raised during allocation is propagated and Container is not modified.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Insert (Container : @key{in out} Map; Key : @key{in} Key_Type; Position : @key{out} Cursor; Inserted : @key{out} Boolean);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Insert inserts Key into Container as per the five-parameter Insert, with the difference that an element initialized with any implicit initial values for any part (as for an @nt{object_declaration} with no initialization expression @em see 3.3.1) is inserted.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Insert (Container : @key{in out} Map; Key : @key{in} Key_Type; New_Item : @key{in} Element_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Insert inserts Key and New_Item into Container as per the five-parameter Insert, with the difference that if a node with a key equivalent to Key is already in the map, then Constraint_Error is propagated.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Leading],Text=[This is equivalent to:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{declare} Inserted : Boolean; C : Cursor; @key{begin} Insert (Container, Key, New_Item, C, Inserted); @key{if not} Inserted @key{then} @key{raise} Constraint_Error; @key{end if}; @key{end};]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[but doesn't require the hassle of @key{out} parameters.]} @end{Ramification} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Include (Container : @key{in out} Map; Key : @key{in} Key_Type; New_Item : @key{in} Element_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Include inserts Key and New_Item into Container as per the five-parameter Insert, with the difference that if a node with a key equivalent to Key is already in the map, then this operation assigns Key and New_Item to the matching node. Any exception raised during assignment is propagated.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Leading],Text=[This is equivalent to:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{declare} C : Cursor := Find (Container, Key); @key{begin} @key{if} C = No_Element @key{then} Insert (Container, Key, New_Item); @key{else} Replace (Container, Key, New_Item); @key{end if}; @key{end};]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[but this avoids doing the search twice.]} @end{Ramification} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Replace (Container : @key{in out} Map; Key : @key{in} Key_Type; New_Item : @key{in} Element_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Replace checks if a node with a key equivalent to Key is present in Container. If a match is found, Replace assigns Key and New_Item to the matching node; otherwise, Constraint_Error is propagated.]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[We update the key as well as the element, as the key might include additional information that does not participate in equivalence. If only the element needs to be updated, use Replace_Element (Find (Container, Key), New_Element).]} @end{Discussion} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Delete (Container : @key{in out} Map; Key : @key{in} Key_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Delete checks if a node with a key equivalent to Key is present in Container. If a match is found, Delete removes the node from the map; otherwise, Constraint_Error is propagated.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Delete (Container : @key{in out} Map; Position : @key{in out} Cursor);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element, then Constraint_Error is propagated. If Position does not designate an element in Container, then Program_Error is propagated. Otherwise, Delete removes the node designated by Position from the map. Position is set to No_Element on return.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The check on Position checks that the cursor does not belong to some other map. This check implies that a reference to the map is included in the cursor value. This wording is not meant to require detection of dangling cursors; such cursors are defined to be invalid, which means that execution is erroneous, and any result is allowed (including not raising an exception).]} @end{Ramification} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Exclude (Container : @key{in out} Map; Key : @key{in} Key_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Exclude checks if a node with a key equivalent to Key is present in Container. If a match is found, Exclude removes the node from the map and then deallocates the node.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Exclude should work on an empty map; nothing happens in that case.]} @end{Ramification} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Contains (Container : Map; Key : Key_Type) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Find (Container, Key) /= No_Element.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Find (Container : Map; Key : Key_Type) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Length (Container) equals 0, then Find returns No_Element. Otherwise, Find checks if a node with a key equivalent to Key is present in Container. If a match is found, a cursor designating the matching node is returned; otherwise, No_Element is returned.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Element (Container : Map; Key : Key_Type) @key{return} Element_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Element (Find (Container, Key)).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} First (Container : Map) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Length (Container) = 0, then First returns No_Element. Otherwise, First returns a cursor that designates the first node in Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Next (Position : Cursor) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns a cursor that designates the successor of the node designated by Position. If Position designates the last node, then No_Element is returned. If Position equals No_Element, then No_Element is returned.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Next (Position : @key{in out} Cursor);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Position := Next (Position).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Has_Element (Position : Cursor) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns True if Position designates a node, and returns False otherwise.]} @begin{Honest} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This function may not detect cursors that designate deleted elements; such cursors are invalid (see below); the result of Has_Element for invalid cursors is unspecified (but not erroneous).]} @end{Honest} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Iterate (Container : @key{in} Map; Process : @key{not null access procedure} (Position : @key{in} Cursor));]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Iterate calls Process.@key{all} with a cursor that designates each node in Container, starting with the first node and moving the cursor according to the successor relation. Program_Error is propagated if Process.@key{all} tampers with the elements of Container. Any exception raised by Process.@key{all} is propagated.]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The @lquotes@;tamper with cursors@rquotes@; check takes place when the operations that insert or delete elements, and so on, are called.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[See Iterate for vectors (@RefSecNum{The Package Containers.Vectors}) for a suggested implementation of the check.]} @end{ImplNote} @end{DescribeCode} @end{StaticSem} @begin{Erron} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[ A Cursor value is @i{invalid} if any of the following have occurred since it was created:@Defn2{Term=[invalid cursor],Sec=[of a map]} @PDefn2{Term=[cursor],Sec=[invalid]}]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The map that contains the node it designates has been finalized;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The map that contains the node it designates has been used as the Source or Target of a call to Move; or]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The node it designates has been deleted from the map.]} @end{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The result of "=" or Has_Element is unspecified if these functions are called with an invalid cursor parameter.@PDefn{unspecified} Execution is erroneous if any other subprogram declared in Containers.Hashed_Maps or Containers.Ordered_Maps is called with an invalid cursor parameter.@PDefn2{Term=(erroneous execution),Sec=(cause)}]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The list above is intended to be exhaustive. In other cases, a cursor value continues to designate its original element. For instance, cursor values survive the insertion and deletion of other nodes.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[While it is possible to check for these cases, in many cases the overhead necessary to make the check is substantial in time or space. Implementations are encouraged to check for as many of these cases as possible and raise Program_Error if detected.]} @end{Discussion} @end{Erron} @begin{ImplReq} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[No storage associated with a Map object shall be lost upon assignment or scope exit.]} @end{ImplReq} @begin{ImplAdvice} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Move should not copy elements, and should minimize copying of internal data structures.]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[Move for a map should not copy elements, and should minimize copying of internal data structures.]}]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Usually that can be accomplished simply by moving the pointer(s) to the internal data structures from the Source container to the Target container.]} @end{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[If an exception is propagated from a map operation, no storage should be lost, nor any elements removed from a map unless specified by the operation.]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[If an exception is propagated from a map operation, no storage should be lost, nor any elements removed from a map unless specified by the operation.]}]} @begin{Reason} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This is important so that programs can recover from errors. But we don't want to require heroic efforts, so we just require documentation of cases where this can't be accomplished.]} @end{Reason} @end{ImplAdvice} @begin{DiffWord95} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[This description of maps is new; the extensions are documented with the specific packages.]} @end{DiffWord95} @LabeledAddedSubclause{Version=[2],Name=[The Package Containers.Hashed_Maps]} @begin{StaticSem} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],KeepNext=[T],Type=[Leading],Text=[The generic library package Containers.Hashed_Maps has the following declaration:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{generic} @key{type} Key_Type @key{is private}; @key{type} Element_Type @key{is private}; @key{with function} Hash (Key : Key_Type) @key{return} Hash_Type; @key{with function} Equivalent_Keys (Left, Right : Key_Type) @key{return} Boolean; @key{with function} "=" (Left, Right : Element_Type) @key{return} Boolean is <>; @key{package} Ada.Containers.Hashed_Maps @key{is}@ChildUnit{Parent=[Ada.Containers],Child=[Hashed_Maps]} @key{pragma} Preelaborate (Hashed_Maps);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{type} @AdaTypeDefn{Map} @key{is tagged private}; @key{pragma} Preelaborable_Initialization(Map);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{type} @AdaTypeDefn{Cursor} @key{is private}; @key{pragma} Preelaborable_Initialization(Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @AdaDefn{Empty_Map} : @key{constant} Map;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @AdaDefn{No_Element} : @key{constant} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "=" (Left, Right : Map) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Length} (Container : Map) @key{return} Count_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Is_Empty} (Container : Map) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Clear} (Container : @key{in out} Map);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Key} (Position : Cursor) @key{return} Key_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Element} (Position : Cursor) @key{return} Element_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Query_Element} (Position : @key{in} Cursor; Process : @key{not null access procedure} (Key : @key{in} Key_Type; Element : @key{in} Element_Type));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Update_Element} (Position : @key{in} Cursor; Process : @key{not null access procedure} (Key : @key{in} Key_Type; Element : @key{in out} Element_Type));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Replace_Element} (Position : @key{in} Cursor; By : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Move} (Target : @key{in out} Map; Source : @key{in out} Map);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert} (Container : @key{in out} Map; Key : @key{in} Key_Type; New_Item : @key{in} Element_Type; Position : @key{out} Cursor; Inserted : @key{out} Boolean);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert} (Container : @key{in out} Map; Key : @key{in} Key_Type; Position : @key{out} Cursor; Inserted : @key{out} Boolean);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert} (Container : @key{in out} Map; Key : @key{in} Key_Type; New_Item : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Include} (Container : @key{in out} Map; Key : @key{in} Key_Type; New_Item : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Replace} (Container : @key{in out} Map; Key : @key{in} Key_Type; New_Item : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete} (Container : @key{in out} Map; Key : @key{in} Key_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete} (Container : @key{in out} Map; Position : @key{in out} Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Exclude} (Container : @key{in out} Map; Key : @key{in} Key_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Contains} (Container : Map; Key : Key_Type) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Find} (Container : Map; Key : Key_Type) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Element} (Container : Map; Key : Key_Type) @key{return} Element_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{First} (Container : Map) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Next} (Position : Cursor) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Next} (Position : @key{in out} Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Has_Element} (Position : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Equivalent_Keys} (Left, Right : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Equivalent_Keys} (Left : Cursor; Right : Key_Type) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Equivalent_Keys} (Left : Key_Type; Right : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Iterate} (Container : @key{in} Map; Process : @key{not null access procedure} (Position : @key{in} Cursor));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Capacity} (Container : Map) @key{return} Count_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Reserve_Capacity} (Container : @key{in out} Map; Capacity : @key{in} Count_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{private}]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ ... -- @RI[not specified by the language]]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{end} Ada.Containers.Hashed_Maps;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[An object of type Map contains an expandable hash table, which is used to provide direct access to nodes. The @i of an object of type Map is the maximum number of nodes that can be inserted into the hash table prior to it being automatically expanded.@Defn2{Term=[capacity],Sec=[of a hashed map]}]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The expected implementation for a Map uses a hash table which is grown when it is too small, with linked lists hanging off of each bucket. Note that in that implementation a cursor needs a back pointer to the Map object to implement iteration; that could either be in the nodes, or in the cursor object. To provide an average O(1) access time, capacity would typically equal the number of buckets in such an implementation, so that the average bucket linked list length would be no more than 1.0.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[There is no defined relationship between elements in a hashed map. Typically, iteration will return elements in the order that they are hashed in.]} @end{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn2{Term={equivalent key},Sec={of a hashed map}} Two keys @i and @i are defined to be @i if Equivalent_Keys (@i, @i) returns True.]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Function Hash is expected to return the same value each time it is called with a particular key value. For any two equivalent key values, Hash is expected to return the same value. If Hash behaves in some other manner, the behavior of this package is unspecified. Which subprograms of this package call Hash, and how many times they call it, is unspecified.@PDefn{unspecified}]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The implementation is not required to protect against Hash raising an exception, or returning random numbers, or any other @lquotes@;bad@rquotes behavior. It's not practical to do so, and a broken Hash function makes the container unusable.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The implementation can call Hash whenever it is needed; we don't want to specify how often that happens. The result must remain the same (this is logically a pure function), or the behavior is unspecified.]} @end{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Function Equivalent_Keys is expected to return the same value each time it is called with a particular pair of key values. For any two keys @i and @i, the boolean values Equivalent_Keys (@i, @i) and Equivalent_Key (@i, @i) are expected to be equal. If Equivalent_Keys behaves in some other manner, the behavior of this package is unspecified. Which subprograms of this package call Equivalent_Keys, and how many times they call it, is unspecified.@PDefn{unspecified}]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[As with Hash, the implementation is not required to protect against Equivalent_Keys raising an exception or returning random results. Similarly, the implementation can call this operation whenever it is needed. The result must remain the same (this is a logically pure function), or the behavior is unspecified.]} @end{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[If the value of a key stored in a node of a map is changed other than by an operation in this package such that at least one of Hash or Equivalent_Keys give different results, the behavior of this package is unspecified.@PDefn{unspecified}]}]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The implementation is not required to protect against changes to key values other than via the operations declared in the Hashed_Maps package.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Leading],Text=[To see how this could happen, imagine an instantiation of Hashed_Maps where the key type is an access-to-variable type and Hash returns a value derived from the components of the designated object. Then, any operation that has a key value could modify those components and change the hash value:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Key (Map).Some_Component := New_Value;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This is really a design error on the part of the user of the map; it shouldn't be possible to modify keys stored in a map. But we can't prevent this error anymore than we can prevent someone passing as Hash a random number generator.]} @end{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn2{Term=[first node],Sec=[of a hashed map]} @Defn2{Term=[last node],Sec=[of a hashed map]} @Defn2{Term=[successor node],Sec=[of a hashed map]}Which nodes are the first node and the last node of a map, and which node is the successor of a given node, are unspecified, other than the general semantics described in @RefSecNum{Maps}.@PDefn{unspecified}]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Typically the first node will be the first node in the first bucket, the last node will be the last node in the last bucket, and the successor will be obtained by following the collision list, and going to the next bucket at the end of each bucket.]} @end{ImplNote} @begin{DescribeCode} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Clear (Container : @key{in out} Map);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[In addition to the semantics described in @RefSecNum{Maps}, Clear does not affect the capacity of Container.]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Leading],Keepnext=[T],Text=[In:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Move (Target : @key{in out} Map; Source : @key{in out} Map);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The intended implementation is that the internal hash table of Target is first deallocated; then the internal hash table is removed from Source and moved to Target.]} @end{ImplNote} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Insert (Container : @key{in out} Map; Key : @key{in} Key_Type; New_Item : @key{in} Element_Type; Position : @key{out} Cursor; Inserted : @key{out} Boolean);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[In addition to the semantics described in (see @RefSecNum{Maps}), if Length (Container) equals Capacity (Container), then Insert first calls Reserve_Capacity to increase the capacity of Container to some larger value.]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Insert should only compare keys that hash to the same bucket in the hash table.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[We specify when Reserve_Capacity is called to bound the overhead of capacity expansion operations (which are potentially expensive). Moreover, expansion can be predicted by comparing Capacity(Map) to Length(Map). Since we don't specify by how much the hash table is expanded, this only can be used to predict the next expansion, not later ones.]} @end{ImplNote} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Leading],Keepnext=[T],Text=[In:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Delete (Container : @key{in out} Map; Key : @key{in} Key_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Delete should only compare keys that hash to the same bucket in the hash table. The node containing the element may be deallocated now, or it may be saved and reused later.]} @end{ImplNote} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Leading],Keepnext=[T],Text=[In:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Exclude (Container : @key{in out} Map; Key : @key{in} Key_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Exclude should only compare keys that hash to the same bucket in the hash table.]} @end{ImplNote} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Leading],Keepnext=[T],Text=[In:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Find (Container : Map; Key : Key_Type) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Find should only compare keys that hash to the same bucket in the hash table.]} @end{ImplNote} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Leading],Keepnext=[T],Text=[In:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} First (Container : Map) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[In a typical implementation, this will be the first node in the lowest numbered hash bucket that contains a node.]} @end{ImplNote} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Leading],Keepnext=[T],Text=[In:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Next (Position : Cursor) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[In a typical implementation, this will return the next node in a bucket; if Position is the last node in a bucket, this will return the first node in the next non-empty bucket.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[A typical implementation will need to a keep a pointer at the map container in the cursor in order to implement this function.]} @end{ImplNote} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Equivalent_Keys (Left, Right : Cursor) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Equivalent_Keys (Key (Left), Key (Right)).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Equivalent_Keys (Left : Cursor; Right : Key_Type) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Equivalent_Keys (Key (Left), Right).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Equivalent_Keys (Left : Key_Type; Right : Cursor) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Equivalent_Keys (Left, Key (Right)).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Capacity (Container : Map) @key{return} Count_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns the capacity of Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Reserve_Capacity (Container : @key{in out} Map; Capacity : @key{in} Count_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Reserve_Capacity allocates a new hash table such that the length of the resulting map can become at least the value Capacity without requiring an additional call to Reserve_Capacity, and is large enough to hold the current length of Container. Reserve_Capacity then rehashes the nodes in Container onto the new hash table. It replaces the old hash table with the new hash table, and then deallocates the old hash table. Any exception raised during allocation is propagated and Container is not modified.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Reserve_Capacity tampers with the cursors of Container.]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This routine is used to preallocate the internal hash table to the specified capacity such that future Inserts do not require expansion of the hash table. Therefore, the implementation should allocate the needed memory to make that true at this point, even though the visible semantics could be preserved by waiting until enough elements are inserted.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[While Reserve_Capacity can be used to reduce the capacity of a map, we do not specify whether an implementation actually supports reduction of the capacity. Since the actual capacity can be anything greater than or equal to Count, an implementation never has to reduce the capacity.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Reserve_Capacity tampers with the cursors, as rehashing probably will change the order that elements are stored in the map.]} @end{ImplNote} @end{DescribeCode} @end{StaticSem} @begin{ImplAdvice} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[If @i is the length of a map, the average time complexity of the subprograms Element, Insert, Include, Replace, Delete, Exclude and Find that take a key parameter should be O(log @i). The average time complexity of the subprograms that take a cursor parameter should be O(1). The average time complexity of Reserve_Capacity should be O(@i).]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[The average time complexity of Element, Insert, Include, Replace, Delete, Exclude and Find operations that take a key parameter for Containers.Hashed_Maps should be O(log @i). The average time complexity of the subprograms of Containers.Hashed_Maps that take a cursor parameter should be O(1).]}]} @begin{Reason} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[We do not mean to overly constrain implementation strategies here. However, it is important for portability that the performance of large containers has roughly the same factors on different implementations. If a program is moved to an implementation for which Find is O(@i), that program could be unusable when the maps are large. We allow O(log @i) access because the proportionality constant and caching effects are likely to be larger than the log factor, and we don't want to discourage innovative implementations.]} @end{Reason} @end{ImplAdvice} @begin{Extend95} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn{extensions to Ada 95} The generic package Ada.Containers.Hashed_Maps is new.]} @end{Extend95} @LabeledAddedSubclause{Version=[2],Name=[The Package Containers.Ordered_Maps]} @begin{StaticSem} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],KeepNext=[T],Type=[Leading],Text=[The generic library package Containers.Ordered_Maps has the following declaration:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{generic} @key{type} Key_Type @key{is private}; @key{type} Element_Type @key{is private}; @key{with function} "<" (Left, Right : Key_Type) @key{return} Boolean @key{is} <>; @key{with function} "=" (Left, Right : Element_Type) @key{return} Boolean @key{is} <>; @key{package} Ada.Containers.Ordered_Maps @key{is}@ChildUnit{Parent=[Ada.Containers],Child=[Ordered_Maps]} @key{pragma} Preelaborate (Ordered_Maps);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{type} @AdaTypeDefn{Map} @key{is tagged private}; @key{pragma} Preelaborable_Initialization(Map);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{type} @AdaTypeDefn{Cursor} @key{is private}; @key{pragma} Preelaborable_Initialization(Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @AdaDefn{Empty_Map} : @key{constant} Map;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @AdaDefn{No_Element} : @key{constant} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "=" (Left, Right : Map) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Length} (Container : Map) @key{return} Count_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Is_Empty} (Container : Map) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Clear} (Container : @key{in out} Map);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Key} (Position : Cursor) @key{return} Key_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Element} (Position : Cursor) @key{return} Element_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Query_Element} (Position : @key{in} Cursor; Process : @key{not null access procedure} (Key : @key{in} Key_Type; Element : @key{in} Element_Type));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Update_Element} (Position : @key{in} Cursor; Process : @key{not null access procedure} (Key : @key{in} Key_Type; Element : @key{in out} Element_Type));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Replace_Element} (Position : @key{in} Cursor; By : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Move} (Target : @key{in out} Map; Source : @key{in out} Map);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert} (Container : @key{in out} Map; Key : @key{in} Key_Type; New_Item : @key{in} Element_Type; Position : @key{out} Cursor; Inserted : @key{out} Boolean);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert} (Container : @key{in out} Map; Key : @key{in} Key_Type; Position : @key{out} Cursor; Inserted : @key{out} Boolean);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert} (Container : @key{in out} Map; Key : @key{in} Key_Type; New_Item : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Include} (Container : @key{in out} Map; Key : @key{in} Key_Type; New_Item : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Replace} (Container : @key{in out} Map; Key : @key{in} Key_Type; New_Item : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete} (Container : @key{in out} Map; Key : @key{in} Key_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete} (Container : @key{in out} Map; Position : @key{in out} Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete_First} (Container : @key{in out} Map);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete_Last} (Container : @key{in out} Map);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Exclude} (Container : @key{in out} Map; Key : @key{in} Key_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Contains} (Container : Map; Key : Key_Type) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Find} (Container : Map; Key : Key_Type) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Element} (Container : Map; Key : Key_Type) @key{return} Element_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Floor} (Container : Map; Key : Key_Type) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Ceiling} (Container : Map; Key : Key_Type) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{First} (Container : Map) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{First_Key} (Container : Map) @key{return} Key_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{First_Element} (Container : Map) @key{return} Element_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Last} (Container : Map) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Last_Key} (Container : Map) @key{return} Key_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Last_Element} (Container : Map) @key{return} Element_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Next} (Position : Cursor) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Next} (Position : @key{in out} Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Previous} (Position : Cursor) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Previous} (Position : @key{in out} Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Has_Element} (Position : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "<" (Left, Right : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} ">" (Left, Right : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "<" (Left : Cursor; Right : Key_Type) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} ">" (Left : Cursor; Right : Key_Type) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "<" (Left : Key_Type; Right : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} ">" (Left : Key_Type; Right : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Iterate} (Container : @key{in} Map; Process : @key{not null access procedure} (Position : @key{in} Cursor));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Reverse_Iterate} (Container : @key{in} Map; Process : @key{not null access procedure} (Position : @key{in} Cursor));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{private}]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ ... -- @RI[not specified by the language]]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{end} Ada.Containers.Ordered_Maps;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn2{Term={equivalent key},Sec={of an ordered map}} Two keys @i and @i are @i if both @i < @i and @i < @i return False, using the generic formal "<" operator for keys.]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Functions "<" and "=" on Key_Type values are expected to return the same result value each time they are called with a particular pair of key values. If @i = @i returns True, then @i = @i is expected to also return True. If @i < @i returns True, then @i < @i is expected to return False. For any two equivalent elements, "=" is expected to return True. If "<" or "=" behaves in some other manner, the behavior of this package is unspecified. Which subprograms of this package call "<" and "=", and how many times these functions are called, is unspecified.@PDefn{unspecified}]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The implementation is not required to protect against "<" or "=" raising an exception, or returning random results, or any other "bad" behavior. It's not practical to do so, and a broken "<" or "=" function makes the container unusable.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The implementation can call "<" and "=" whenever it is needed; we don't want to specify how often that happens. The result must remain the same (these are logically pure functions), or the behavior is unspecified.]} @end{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[If the value of a key stored in a map is changed other than by an operation in this package such that at least one of "<" or "=" give different results, the behavior of this package is unspecified.@PDefn{unspecified}]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The implementation is not required to protect against changes to key values other than via the operations declared in the Ordered_Maps package.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Leading],Text=[To see how this could happen, imagine an instantiation of Ordered_Maps package where the key type is an access-to-variable type and "<" returns a value derived from comparing the components of the designated objects. Then, any operation that has a key value (even if the key value is constant) could modify those components and change the result of "<":]} @begin{example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Key (Map).Some_Component := New_Value;]} @end{example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This is really a design error on the part of the user of the map; it shouldn't be possible to modify keys stored in a map such that "<" changes. But we can't prevent this error anymore than we can prevent someone passing as "<" a routine that produces random answers.]} @end{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn2{Term=[first node],Sec=[of an ordered map]} @Defn2{Term=[last node],Sec=[of an ordered map]} @Defn2{Term=[successor node],Sec=[of an ordered map]} The first node of a nonempty map is the one whose key is less than the key of all the other nodes in the map. The last node of a nonempty map is the one whose key is greater than the key of all the other elements in the map. The successor of a node is the node with the smallest key that is larger than the key of the given node. The predecessor of a node is the node with the largest key that is smaller than the key of the given node. All comparisons are done using the generic formal "<" operator for keys.]} @begin{DescribeCode} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Delete_First (Container : @key{in out} Map);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Container is empty, Delete_First has no effect. Otherwise the node designated by First (Container) is removed from Container. Delete_First tampers with the cursors of Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Delete_Last (Container : @key{in out} Map);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Container is empty, Delete_Last has no effect. Otherwise the node designated by Last (Container) is removed from Container. Delete_Last tampers with the cursors of Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Floor (Container : Map; Key : Key_Type) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Floor searches for the last node whose key is not greater than Key. If such a node is found, a cursor that designates it is returned. Otherwise No_Element is returned.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Ceiling (Container : Map; Key : Key_Type) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Ceiling searches for the first node whose key is not less than Key, using the generic formal "<" operator for keys. If such a node is found, a cursor that designates it is returned. Otherwise No_Element is returned.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} First_Key (Container : Map) @key{return} Key_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Key (First (Container)).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} First_Element (Container : Map) @key{return} Element_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Element (First (Container)).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Last (Container : Map) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns a cursor that designates the last node in Container. If Container is empty, returns No_Element.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Last_Key (Container : Map) @key{return} Key_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Key (Last (Container)).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Last_Element (Container : Map) @key{return} Element_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Element (Last (Container)).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Previous (Position : Cursor) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element, then Previous returns No_Element. Otherwise Previous returns the a cursor designating the node that precedes the one designated by Position. If Position designates the first element, then Previous returns No_Element.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Previous (Position : @key{in out} Cursor);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Position := Previous (Position).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} "<" (Left, Right : Cursor) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Key (Left) < Key (Right).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} ">" (Left, Right : Cursor) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Key (Right) < Key (Left).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} "<" (Left : Cursor; Right : Key_Type) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Key (Left) < Right.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} ">" (Left : Cursor; Right : Key_Type) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Right < Key (Left).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} "<" (Left : Key_Type; Right : Cursor) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Left < Key (Right).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} ">" (Left : Key_Type; Right : Cursor) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Key (Right) < Left.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Reverse_Iterate (Container : @key{in} Map; Process : @key{not null access procedure} (Position : @key{in} Cursor));]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Iterates over the nodes in Container as per Iterate, with the difference that the nodes are traversed in predecessor order, starting with the last node.]} @end{DescribeCode} @end{StaticSem} @begin{ImplAdvice} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[If @i is the length of a map, then the worst-case time complexity of the Element, Insert, Include, Replace, Delete, Exclude and Find operations that take a key parameter should be O((log @i)**2) or better. The worst-case time complexity of the subprograms that take a cursor parameter should be O(1).]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[The worst-case time complexity of Element, Insert, Include, Replace, Delete, Exclude and Find operations that take a key parameter for Containers.Ordered_Maps should be O((log @i)**2) or better. The worst-case time complexity of the subprograms of Containers.Ordered_Maps that take a cursor parameter should be O(1).]}]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[A balanced (red-black) tree for keys has O(log @i) worst-case performance. Note that a O(@i) worst-case implementation (like a list) would be wrong.]} @end{ImplNote} @begin{Reason} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[We do not mean to overly constrain implementation strategies here. However, it is important for portability that the performance of large containers has roughly the same factors on different implementations. If a program is moved to an implementation that takes O(@i) to find elements, that program could be unusable when the maps are large. We allow the extra log @i factors because the proportionality constant and caching effects are likely to be larger than the log factor, and we don't want to discourage innovative implementations.]} @end{Reason} @end{ImplAdvice} @begin{Extend95} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn{extensions to Ada 95} The generic package Ada.Containers.Ordered_Maps is new.]} @end{Extend95} @LabeledAddedSubclause{Version=[2],Name=[Sets]} @begin{Intro} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The language-defined generic packages Containers.Hashed_Sets and Containers.Ordered_Sets provide private types Set and Cursor, and a set of operations for each type. A set container allows elements of an arbitrary type to be stored without duplication. A hashed set uses a hash function to organize elements, while an ordered set orders its element per a specified relation.@Defn{set container} @Defn2{Term=[container],Sec=[set]}]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[This section describes the declarations that are common to both kinds of sets. See @RefSecNum{The Package Containers.Hashed_Sets} for a description of the semantics specific to Containers.Hashed_Sets and @RefSecNum{The Package Containers.Ordered_Sets} for a description of the semantics specific to Containers.Ordered_Sets.]} @end{Intro} @begin{StaticSem} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The type Set is used to represent sets. The type Set needs finalization (see @RefSecNum{User-Defined Assignment and Finalization}).]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[A set contains elements. Set cursors designate elements. There exists an equivalence relation on elements, whose definition is different for hashed sets and ordered sets. A set never contains two or more equivalent elements. The @i{length} of a set is the number of elements it contains.@Defn2{Term={length},Sec={of a set}}]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn2{Term=[first element],Sec=[of a set]} @Defn2{Term=[last element],Sec=[of a set]} @Defn2{Term=[successor element],Sec=[of a set]} Each nonempty set has two particular elements called the @i{first element} and the @i{last element} (which may be the same). Each element except for the last element has a @i{successor element}. If there are no other intervening operations, starting with the first element and repeatedly going to the successor element will visit each element in the map exactly once until the last element is reached. The exact definition of these terms is different for hashed sets and ordered sets.]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[@Defn2{Term=[tamper with cursors],Sec=[of a set]} Some operations are assumed to work on a constant set of elements. For such an operation, a subprogram is said to @i{tamper with cursors} of a set object @i{S} if:]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it inserts or deletes elements of @i{S}, that is, it calls the Insert, Include, Clear, Delete, Exclude, or Replace_Element procedures with @i{S} as a parameter; or]} @begin{Honest} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Operations which are defined to be equivalent to a call on one of these operations also are included. Similarly, operations which call one of these as part of their definition are included.]} @end{Honest} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[We have to include Replace_Element here because it might delete and reinsert the element if it moves in the set.]} @end{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it finalizes @i; or]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it calls the Move procedure with @i as a parameter; or]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it calls one of the operations defined to tamper with cursors of @i.]} @end{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[@Defn2{Term=[tamper with elements],Sec=[of a set]} Some operations are assumed to not replace elements. For such an operation, a subprogram is said to @i of a set object @i if:]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it tampers with cursors of @i; or]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[it replaces one or more elements of @i, that is, it calls the Replace or Replace_Element procedures with @i as a parameter.]} @begin{Reason} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Complete replacement of an element can cause its memory to be deallocated while another operation is holding onto a reference to it. That can't be allowed. However, a simple modification of (part of) an element is not a problem, so Update_Element_Preserving_Key does not cause a problem.]} @end{Reason} @end{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Empty_Set represents the empty Set object. It has a length of 0. If an object of type Set is not otherwise initialized, it is initialized to the same value as Empty_Set.]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[No_Element represents a cursor that designates no element. If an object of type Cursor is not otherwise initialized, it is initialized to the same value as No_Element.]} @begin{DescribeCode} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} "=" (Left, Right : Set) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Left and Right denote the same set object, then the function returns True. If Left and Right have different lengths, then the function returns False. Otherwise, for each element @i in Left, the function returns False if an element equal to @i (in the sense of the generic formal equality operator) is not present in Right. If the function has not returned a result after checking all of the elements, it returns True. Any exception raised during evaluation of element equality is propagated.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Equivalent_Sets (Left, Right : Set) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Left and Right denote the same set object, then the function returns True. If Left and Right have different lengths, then the function returns False. Otherwise, for each element @i in Left, the function returns False if an element equivalent to @i is not present in Right. If the function has not returned a result after checking all of the elements, it returns True. Any exception raised during evaluation of element equivalence is propagated.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Length (Container : Set) @key{return} Count_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns the number of elements in Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Is_Empty (Container : Set) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Length (Container) = 0.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Clear (Container : @key{in out} Set);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Removes all the elements from Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Element (Position : Cursor) @key{return} Element_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element, then Constraint_Error is propagated. Otherwise, Element returns the element designated by Position.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Query_Element (Position : @key{in} Cursor; Process : @key{not null access procedure} (Element : @key{in} Element_Type));]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element, then Constraint_Error is propagated. Otherwise, Query_Element calls Process.@key{all} with the element designated by Position as the argument. Program_Error is propagated if Process.@key{all} tampers with the elements of Container. Any exceptions raised by Process.@key{all} are propagated.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Replace_Element (Container : @key{in} Set; Position : @key{in} Cursor; By : @key{in} Element_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element, then Constraint_Error is propagated. If Position does not designate an element in Container, then Program_Error is propagated. Otherwise, the element designated by Position is tested for equivalence to By; if they are found to be equivalent, Replace_Element assigns By to the element designated by Position. Otherwise, the element designated by Position is removed from the container, then By is inserted into the container. If the insertion fails, Program_Error is propagated.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Move (Target : @key{in out} Set; Source : @key{in out} Set);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Target denotes the same object as Source, then Move has no effect. Otherwise, Move first clears Target. Then, each element from Source is removed from Source and inserted into Target. The length of Source is 0 after a successful call to Move.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Insert (Container : @key{in out} Set; New_Item : @key{in} Element_Type; Position : @key{out} Cursor; Inserted : @key{out} Boolean);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Insert checks if an element equivalent to New_Item is already present in Container. If a match is found, Inserted is set to False and Position designates the matching element. Otherwise, Insert adds New_Item to Container; Inserted is set to True and Position designates the newly-inserted element. Any exception raised during allocation is propagated and Container is not modified.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Insert (Container : @key{in out} Set; New_Item : @key{in} Element_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Insert inserts New_Item into Container as per the four-parameter Insert, with the difference that if an element equivalent to New_Item is already in the set, then Constraint_Error is propagated.]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Leading],Text=[This is equivalent to:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{declare} Inserted : Boolean; C : Cursor; @key{begin} Insert (Container, New_Item, C, Inserted); @key{if not} Inserted @key{then} @key{raise} Constraint_Error; @key{end if}; @key{end};]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[but doesn't require the hassle of @key{out} parameters.]} @end{Discussion} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Include (Container : @key{in out} Set; New_Item : @key{in} Element_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Include inserts New_Item into Container as per the four-parameter Insert, with the difference that if an element equivalent to New_Item is already in the set, then it is replaced. Any exception raised during assignment is propagated.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Replace (Container : @key{in out} Set; New_Item : @key{in} Element_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Replace checks if an element equivalent to New_Item is already in the set. If a match is found, that element is replaced with New_Item; otherwise, Constraint_Error is propagated.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Delete (Container : @key{in out} Set; Item : @key{in} Element_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Delete checks if an element equivalent to Item is present in Container. If a match is found, Delete removes the element from the set; otherwise, Constraint_Error is propagated.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Delete (Container : @key{in out} Set; Position : @key{in out} Cursor);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element, Delete has no effect. If Position does not designate an element in Container, then Program_Error is propagated. Otherwise, Delete removes the node designated by Position from the set. Position is set to No_Element on return.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The check on Position checks that the cursor does not belong to some other set. This check implies that a reference to the set is included in the cursor value. This wording is not meant to require detection of dangling cursors; such cursors are defined to be invalid, which means that execution is erroneous, and any result is allowed (including not raising an exception).]} @end{Ramification} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Exclude (Container : @key{in out} Set; Item : @key{in} Element_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Exclude checks if an element equivalent to Item is present in Container. If a match is found, Exclude removes the element from the set.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Contains (Container : Set; Item : Element_Type) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Find (Container, Item) /= No_Element.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Find (Container : Set; Item : Element_Type) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Length (Container) equals 0, then Find returns No_Element. Otherwise, Find checks if an element equivalent to Item is present in Container. If a match is found, a cursor designating the matching element is returned; otherwise, No_Element is returned.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} First (Container : Set) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Length (Container) = 0, then First returns No_Element. Otherwise, First returns a cursor that designates the first node in Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Next (Position : Cursor) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns a cursor that designates the successor of the element designated by Position. If Position designates the last element, then No_Element is returned. If Position equals No_Element, then No_Element is returned.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Next (Position : @key{in out} Cursor);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Position := Next (Position).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Has_Element (Position : Cursor) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns True if Position designates an element, and returns False otherwise.]} @begin{Honest} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This function may not detect cursors that designate deleted elements; such cursors are invalid (see below); the result of Has_Element for invalid cursors is unspecified (but not erroneous).]} @end{Honest} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Iterate (Container : @key{in} Set; Process : @key{not null access procedure} (Position : @key{in} Cursor));]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Iterate calls Process.@key{all} with a cursor that designates each element in Container, starting with the first node and moving the cursor according to the successor relation. Program_Error is propagated if Process.@key{all} tampers with the elements of Container. Any exception raised by Process.@key{all} is propagated.]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The @lquotes@;tamper with elements@rquotes@; check takes place when the operations that insert or delete elements, and so on are called.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[See Iterate for vectors (@RefSecNum{The Package Containers.Vectors}) for a suggested implementation of the check.]} @end{ImplNote} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Union (Target : @key{in out} Set; Source : @key{in} Set);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Union inserts into Target the elements of Source that are not equivalent to some element already in Target.]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[If the objects are the same, the result is the same as the original object. The implementation needs to take care so that aliasing effects do not make the result trash; Union (S, S); must work.]} @end{ImplNote} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Union (Left, Right : Set) @key{return} Set;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns a set comprising all of the elements of Left, and the elements of Right that are not equivalent to some element of Left.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Intersection (Target : @key{in out} Set; Source : @key{in} Set);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Union deletes from Target the elements of Target that are not equivalent to some element of Source.]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[If the objects are the same, the result is the same as the original object. The implementation needs to take care so that aliasing effects do not make the result trash; Intersection (S, S); must work.]} @end{ImplNote} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Intersection (Left, Right : Set) @key{return} Set;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns a set comprising all the elements of Left that are equivalent to the some element of Right.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Difference (Target : @key{in out} Set; Source : @key{in} Set);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Target denotes the same object as Source, then Difference clears Target. Otherwise, it deletes from Target the elements that are equivalent to some element of Source.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Difference (Left, Right : Set) @key{return} Set;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns a set comprising the elements of Left that are not equivalent to some element of Right.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Symmetric_Difference (Target : @key{in out} Set; Source : @key{in} Set);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Target denotes the same object as Source, then Symmetric_Difference clears Target. Otherwise, it deletes from Target the elements that are equivalent to some element of Source, and inserts into Target the elements of Source that are not equivalent to some element of Target.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Symmetric_Difference (Left, Right : Set) @key{return} Set;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns a set comprising the elements of Left that are not equivalent to some element of Right, and the elements of Right that are not equivalent to some element of Left.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Overlap (Left, Right : Set) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If an element of Left is equivalent to some element of Right, then Overlap returns True. Otherwise it returns False.]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This operation is commutative. If Overlap returns False, the two sets are disjoint.]} @end{Discussion} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Is_Subset (Subset : Set; Of_Set : Set) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If an element of Subset is not equivalent to some element of Of_Set, then Is_Subset returns False. Otherwise it returns True.]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This operation is not commutative, so we use parameter names that make it clear in named notation which set is which.]} @end{Discussion} @end{DescribeCode} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Both Containers.Hashed_Set and Containers.Ordered_Set declare a nested generic package Generic_Keys, which provides operations that allow set manipulation in terms of a key (typically, a portion of an element) instead of a complete element. The formal function Key of Generic_Keys extracts a key value from an element. It is expected to return the same value each time it is called with a particular element. The behavior of Generic_Keys is unspecified if Key behaves in some other manner.@PDefn{unspecified}]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[A key is expected to unambiguously determine one equivalence class for elements. The behavior of Generic_Keys is unspecified if the formal parameters of this package behave in some other manner.@PDefn{unspecified}]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The subprograms in package Generic_Keys named Contains, Find, Element, Delete, and Exclude, are equivalent to the corresponding subprograms in the parent package, with the difference that the Key parameter is used locate an element in the set.]} @begin{DescribeCode} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Replace (Container : @key{in out} Set; Key : @key{in} Key_Type; New_Item : @key{in} Element_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Replace_Element (Container, Find (Container, Key), New_Item).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Key (Position : Cursor) @key{return} Key_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Key (Element (Position)).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Update_Element_Preserving_Key (Container : @key{in out} Set; Position : @key{in} Cursor; Process : @key{not null access procedure} (Element : @key{in out} Element_Type));]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[If Position equals No_Element, then Constraint_Error is propagated. If Position does not designate an element in Container, then Program_Error is propagated. Otherwise, Update_Element_Preserving_Key uses Key to save the key value @i of the element designated by Position. Update_Element_Preserving_Key then calls Process.@key{all} with that element as the argument. Program_Error is propagated if Process.@key{all} tampers with the elements of Container. Any exception raised by Process.@key{all} is propagated. After Process.@key{all} returns, Update_Element_Preserving_Key checks if @i determines the same equivalence class as that for the new element; if not, the element is removed from the set and Program_Error is propagated.]} @begin{Reason} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The key check ensures that the invariants of the set are preserved by the modification. The @lquotes@;tampers with elements@rquotes@; check prevents data loss (if Element_Type is by-copy) or erroneous execution (if element type is unconstrained and indefinite).]} @end{Reason} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Element_Type is unconstrained and definite, then the Element parameter of Process.@key{all} shall be unconstrained.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This means that the elements cannot be directly allocated from the heap; it must be possible to change the discriminants of the element in place.]} @end{Ramification} @end{DescribeCode} @end{StaticSem} @begin{Erron} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[ A Cursor value is @i if any of the following have occurred since it was created:@Defn2{Term=[invalid cursor],Sec=[of a set]} @PDefn2{Term=[cursor],Sec=[invalid]}]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The set that contains the element it designates has been finalized;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The set that contains the element it designates has been used as the Source or Target of a call to Move; or]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The element it designates has been deleted from the set.]} @end{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The result of "=" or Has_Element is unspecified if these functions are called with an invalid cursor parameter.@PDefn{unspecified} Execution is erroneous if any other subprogram declared in Containers.Hashed_Sets or Containers.Ordered_Sets is called with an invalid cursor parameter.@PDefn2{Term=(erroneous execution),Sec=(cause)}]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The list above is intended to be exhaustive. In other cases, a cursor value continues to designate its original element. For instance, cursor values survive the insertion and deletion of other elements.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[While it is possible to check for these cases, in many cases the overhead necessary to make the check is substantial in time or space. Implementations are encouraged to check for as many of these cases as possible and raise Program_Error if detected.]} @end{Discussion} @end{Erron} @begin{ImplReq} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[No storage associated with a Set object shall be lost upon assignment or scope exit.]} @end{ImplReq} @begin{ImplAdvice} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Move should not copy elements, and should minimize copying of internal data structures.]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[Move for sets should not copy elements, and should minimize copying of internal data structures.]}]} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Usually that can be accomplished simply by moving the pointer(s) to the internal data structures from the Source container to the Target container.]} @end{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[If an exception is propagated from a set operation, no storage should be lost, nor any elements removed from a set unless specified by the operation.]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[If an exception is propagated from a set operation, no storage should be lost, nor any elements removed from a set unless specified by the operation.]}]} @begin{Reason} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This is important so that programs can recover from errors. But we don't want to require heroic efforts, so we just require documentation of cases where this can't be accomplished.]} @end{Reason} @end{ImplAdvice} @begin{DiffWord95} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[This description of sets is new; the extensions are documented with the specific packages.]} @end{DiffWord95} @LabeledAddedSubclause{Version=[2],Name=[The Package Containers.Hashed_Sets]} @begin{StaticSem} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],KeepNext=[T],Type=[Leading],Text=[The generic library package Containers.Hashed_Sets has the following declaration:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{generic} @key{type} Element_Type @key{is private}; @key{with function} Hash (Element : Element_Type) @key{return} Hash_Type; @key{with function} Equivalent_Elements (Left, Right : Element_Type) @key{return} Boolean; @key{with function} "=" (Left, Right : Element_Type) @key{return} Boolean @key{is} <>; @key{package} Ada.Containers.Hashed_Sets @key{is}@ChildUnit{Parent=[Ada.Containers],Child=[Hashed_Sets]} @key{pragma} Preelaborate (Hashed_Sets);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{type} @AdaTypeDefn{Set} @key{is tagged private}; @key{pragma} Preelaborable_Initialization(Set);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{type} @AdaTypeDefn{Cursor} @key{is private}; @key{pragma} Preelaborable_Initialization(Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @AdaDefn{Empty_Set} : @key{constant} Set;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @AdaDefn{No_Element} : @key{constant} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "=" (Left, Right : Set) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Equivalent_Sets} (Left, Right : Set) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Length} (Container : Set) @key{return} Count_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Is_Empty} (Container : Set) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Clear} (Container : @key{in out} Set);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Element} (Position : Cursor) @key{return} Element_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Query_Element} (Position : @key{in} Cursor; Process : @key{not null access procedure} (Element : @key{in} Element_Type));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Replace_Element} (Container : @key{in} Set; Position : @key{in} Cursor; By : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Move} (Target : @key{in out} Set; Source : @key{in out} Set);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert} (Container : @key{in out} Set; New_Item : @key{in} Element_Type; Position : @key{out} Cursor; Inserted : @key{out} Boolean);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert} (Container : @key{in out} Set; New_Item : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Include} (Container : @key{in out} Set; New_Item : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Replace} (Container : @key{in out} Set; New_Item : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete} (Container : @key{in out} Set; Item : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete} (Container : @key{in out} Set; Position : @key{in out} Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Exclude} (Container : @key{in out} Set; Item : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Contains} (Container : Set; Item : Element_Type) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Find} (Container : Set; Item : Element_Type) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{First} (Container : Set) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Next} (Position : Cursor) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Next} (Position : @key{in out} Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Has_Element} (Position : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Equivalent_Elements} (Left, Right : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Equivalent_Elements} (Left : Cursor; Right : Element_Type) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Equivalent_Elements} (Left : Element_Type; Right : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Iterate} (Container : @key{in} Set; Process : @key{not null access procedure} (Position : @key{in} Cursor));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Union} (Target : @key{in out} Set; Source : @key{in} Set);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Union} (Left, Right : Set) @key{return} Set;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "@key{or}" (Left, Right : Set) @key{return} Set @key{renames} Union;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Intersection} (Target : @key{in out} Set; Source : @key{in} Set);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Intersection} (Left, Right : Set) @key{return} Set;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "@key{and}" (Left, Right : Set) @key{return} Set @key{renames} Intersection;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Difference} (Target : @key{in out} Set; Source : @key{in} Set);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Difference} (Left, Right : Set) @key{return} Set;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "-" (Left, Right : Set) @key{return} Set @key{renames} Difference;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Symmetric_Difference} (Target : @key{in out} Set; Source : @key{in} Set);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Symmetric_Difference} (Left, Right : Set) @key{return} Set;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "@key{xor}" (Left, Right : Set) @key{return} Set @key{renames} Symmetric_Difference;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Overlap} (Left, Right : Set) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Is_Subset} (Subset : Set; Of_Set : Set) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Capacity} (Container : Set) @key{return} Count_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Reserve_Capacity} (Container : @key{in out} Set; Capacity : @key{in} Count_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{generic} @key{type} Key_Type (<>) @key{is limited private}; @key{with function} Key (Element : @key{in} Element_Type) @key{return} Key_Type; @key{with function} Hash (Key : Key_Type) @key{return} Hash_Type; @key{with function} Equivalent_Keys (Left : Key_Type; Right : Element_Type) @key{return} Boolean; @key{package} @AdaDefn{Generic_Keys} @key{is}]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Contains} (Container : Set; Key : Key_Type) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Find} (Container : Set; Key : Key_Type) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Key} (Position : Cursor) @key{return} Key_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Element} (Container : Set; Key : Key_Type) @key{return} Element_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Replace} (Container : @key{in out} Set; Key : @key{in} Key_Type; New_Item : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete} (Container : @key{in out} Set; Key : @key{in} Key_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Exclude} (Container : @key{in out} Set; Key : @key{in} Key_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Update_Element_Preserving_Key} (Container : @key{in out} Set; Position : @key{in} Cursor; Process : @key{not null access procedure} (Element : @key{in out} Element_Type));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Equivalent_Keys} (Left : Cursor; Right : Key_Type) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Equivalent_Keys} (Left : Key_Type; Right : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{end} Generic_Keys;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{private}]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ ... -- @RI[not specified by the language]]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{end} Ada.Containers.Hashed_Sets;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn2{Term=[capacity],Sec=[of a hashed set]} An object of type Set contains an expandable hash table, which is used to provide direct access to elements. The @i of an object of type Set is the maximum number of elements that can be inserted into the hash table prior to it being automatically expanded.]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn2{Term=[equivalent element],Sec=[of a hashed set]} Two elements @i and @i are defined to be @i if Equivalent_Elements (@i, @i) returns True.]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Function Hash is expected to return the same value each time it is called with a particular element value. For any two equivalent elements, Hash is expected to return the same value. If Hash behaves in some other manner, the behavior of this package is unspecified. Which subprograms of this package call Hash, and how many times they call it, is unspecified.@PDefn{unspecified}]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Function Equivalent_Elements is expected to return the same value each time it is called with a particular pair of element values. For any two elements @i and @i, the boolean values Equivalent_Elements (@i, @i) and Equivalent_Elements (@i, @i) are expected to be equal. If Equivalent_Elements behaves in some other manner, the behavior of this package is unspecified. Which subprograms of this package call Equivalent_Elements, and how many times they call it, is unspecified. @PDefn{unspecified}]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[If the value of an element stored in a set is changed other than by an operation in this package such that at least one of Hash or Equivalent_Elements give different results, the behavior of this package is unspecified.@PDefn{unspecified}]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[See @RefSec{The Package Containers.Hashed_Maps} for a suggested implementation, and for justification of the restrictions regarding Hash and Equivalent_Elements. Note that sets only need to store elements, not key/element pairs.]} @end{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn2{Term=[first element],Sec=[of a hashed set]} @Defn2{Term=[last element],Sec=[of a hashed set]} @Defn2{Term=[successor element],Sec=[of a hashed set]} Which elements are the first element and the last element of a set, and which element is the successor of a given element, are unspecified, other than the general semantics described in @RefSecNum{Sets}).@PDefn{unspecified}]} @begin{DescribeCode} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Clear (Container : @key{in out} Set);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[In addition to the semantics described in @RefSecNum{Sets}, Clear does not affect the capacity of Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Insert (Container : @key{in out} Set; New_Item : @key{in} Element_Type; Position : @key{out} Cursor; Inserted : @key{out} Boolean);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[In addition to the semantics described in @RefSecNum{Sets}, if Length (Container) equals Capacity (Container), then Insert first calls Reserve_Capacity to increase the capacity of Container to some larger value.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} First (Container : Set) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Length (Container) = 0, then First returns No_Element. Otherwise, First returns a cursor that designates the first hashed element in Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Equivalent_Elements (Left, Right : Cursor) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Equivalent_Elements (Element (Left), Element (Right)).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Equivalent_Elements (Left : Cursor; Right : Element_Type) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Equivalent_Elements (Element (Left), Right).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Equivalent_Elements (Left : Element_Type; Right : Cursor) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Equivalent_Elements (Left, Element (Right)).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Capacity (Container : Set) @key{return} Count_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns the capacity of Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Reserve_Capacity (Container : @key{in out} Set; Capacity : @key{in} Count_Type);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Reserve_Capacity allocates a new hash table such that the length of the resulting set can become at least the value Capacity without requiring an additional call to Reserve_Capacity, and is large enough to hold the current length of Container. Reserve_Capacity then rehashes the elements in Container onto the new hash table. It replaces the old hash table with the new hash table, and then deallocates the old hash table. Any exception raised during allocation is propagated and Container is not modified.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Reserve_Capacity tampers with the cursors of Container.]} @begin{Reason} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Reserve_Capacity tampers with the cursors, as rehashing probably will change the relationships of the elements in Container.]} @end{Reason} @end{DescribeCode} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[For any element @i{E}, the function Generic_Keys.Hash must be such that Hash (@i{E}) = Generic_Keys.Hash (Key (@i{E})). If Key or Generic_Keys.Hash behave in some other manner, the behavior of Generic_Keys is unspecified. Which subprograms of Generic_Keys call Generic_Keys.Hash, and how many times they call it, is unspecified.@PDefn{unspecified}]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[For any two elements @i{E1} and @i{E2}, the boolean values Equivalent_Element (@i{E1}, @i{E2}), Equivalent_Keys (Key (@i{E1}), @i{E2}), and Equivalent_Keys (Key (@i{E2}), @i{E1}) are all expected to be equal. If Key or Equivalent behave in some other manner, the behavior of Generic_Keys is unspecified. Which subprograms of Generic_Keys call Equivalent, and how many times they call it, is unspecified.@PDefn{unspecified}]} @begin{DescribeCode} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Equivalent_Keys (Left : Cursor; Right : Key_Type) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Equivalent_Keys (Key (Left), Right).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Equivalent_Keys (Left : Key_Type; Right : Cursor) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Equivalent_Keys (Left, Key (Right)).]} @end{DescribeCode} @end{StaticSem} @begin{ImplAdvice} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[If @i is the length of a set, the average time complexity of the subprograms Insert, Include, Replace, Delete, Exclude and Find that take an element parameter should be O(log @i). The average time complexity of the subprograms that take a cursor parameter should be O(1). The average time complexity of Reserve_Capacity should be O(@i).]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[The average time complexity of the Insert, Include, Replace, Delete, Exclude and Find operations of Containers.Hashed_Sets that take an element parameter should be O(log @i). The average time complexity of the subprograms of Containers.Hashed_Sets that take a cursor parameter should be O(1). The average time complexity of Containers.Hashed_Sets.Reserve_Capacity should be O(@i).]}]} @end{ImplAdvice} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[See @RefSec{The Package Containers.Hashed_Maps} for implementation notes regarding some of the operations of this package.]} @end{ImplNote} @begin{Extend95} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn{extensions to Ada 95} The generic package Ada.Containers.Hashed_Sets is new.]} @end{Extend95} @LabeledAddedSubclause{Version=[2],Name=[The Package Containers.Ordered_Sets]} @begin{StaticSem} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],KeepNext=[T],Type=[Leading],Text=[The generic library package Containers.Ordered_Sets has the following declaration:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{generic} @key{type} Element_Type @key{is private}; @key{with function} "<" (Left, Right : Element_Type) @key{return} Boolean @key{is} <>; @key{with function} "=" (Left, Right : Element_Type) @key{return} Boolean @key{is} <>; @key{package} Ada.Containers.Ordered_Sets @key{is}@ChildUnit{Parent=[Ada.Containers],Child=[Ordered_Sets]} @key{pragma} Preelaborate (Ordered_Sets);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{type} @AdaTypeDefn{Set} @key{is tagged private}; @key{pragma} Preelaborable_Initialization(Set);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{type} @AdaTypeDefn{Cursor} @key{is private}; @key{pragma} Preelaborable_Initialization(Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @AdaDefn{Empty_Set} : @key{constant} Set;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @AdaDefn{No_Element} : @key{constant} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "=" (Left, Right : Set) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Equivalent_Sets} (Left, Right : Set) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Length} (Container : Set) @key{return} Count_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Is_Empty} (Container : Set) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Clear} (Container : @key{in out} Set);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Element} (Position : Cursor) @key{return} Element_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Query_Element} (Position : @key{in} Cursor; Process : @key{not null access procedure} (Element : @key{in} Element_Type));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Replace_Element} (Container : @key{in} Set; Position : @key{in} Cursor; By : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Move} (Target : @key{in out} Set; Source : @key{in out} Set);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert} (Container : @key{in out} Set; New_Item : @key{in} Element_Type; Position : @key{out} Cursor; Inserted : @key{out} Boolean);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Insert} (Container : @key{in out} Set; New_Item : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Include} (Container : @key{in out} Set; New_Item : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Replace} (Container : @key{in out} Set; New_Item : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete} (Container : @key{in out} Set; Item : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Exclude} (Container : @key{in out} Set; Item : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete} (Container : @key{in out} Set; Position : @key{in out} Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete_First} (Container : @key{in out} Set);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete_Last} (Container : @key{in out} Set);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Union} (Target : @key{in out} Set; Source : @key{in} Set);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Union} (Left, Right : Set) @key{return} Set;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "@key{or}" (Left, Right : Set) @key{return} Set @key{renames} Union;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Intersection} (Target : @key{in out} Set; Source : @key{in} Set);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Intersection} (Left, Right : Set) @key{return} Set;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "@key{and}" (Left, Right : Set) @key{return} Set @key{renames} Intersection;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Difference} (Target : @key{in out} Set; Source : @key{in} Set);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Difference} (Left, Right : Set) @key{return} Set;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "-" (Left, Right : Set) @key{return} Set @key{renames} Difference;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Symmetric_Difference} (Target : @key{in out} Set; Source : @key{in} Set);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Symmetric_Difference} (Left, Right : Set) @key{return} Set;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "@key{xor}" (Left, Right : Set) @key{return} Set @key{renames} Symmetric_Difference;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Overlap} (Left, Right : Set) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Is_Subset} (Subset : Set; Of_Set : Set) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Contains} (Container : Set; Item : Element_Type) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Find} (Container : Set; Item : Element_Type) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Floor} (Container : Set; Item : Element_Type) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Ceiling} (Container : Set; Item : Element_Type) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{First} (Container : Set) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{First_Element} (Container : Set) @key{return} Element_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Last} (Container : Set) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Last_Element} (Container : Set) @key{return} Element_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Next} (Position : Cursor) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Next} (Position : @key{in out} Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Previous} (Position : Cursor) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Previous} (Position : @key{in out} Cursor);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Has_Element} (Position : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "<" (Left, Right : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} ">" (Left, Right : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "<" (Left : Cursor; Right : Element_Type) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} ">" (Left : Cursor; Right : Element_Type) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "<" (Left : Element_Type; Right : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} ">" (Left : Element_Type; Right : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Iterate} (Container : @key{in} Set;]} Process : @key{not null access procedure} (Position : @key{in} Cursor));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Reverse_Iterate} (Container : @key{in} Set; Process : @key{not null access procedure} (Position : @key{in} Cursor));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{generic} @key{type} Key_Type (<>) @key{is limited private}; @key{with function} Key (Element : Element_Type) @key{return} Key_Type; @key{with function} "<" (Left : Key_Type; Right : Element_Type) @key{return} Boolean @key{is} <>; @key{with function} ">" (Left : Key_Type; Right : Element_Type) @key{return} Boolean @key{is} <>; @key{package} @AdaDefn{Generic_Keys} @key{is}]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Contains} (Container : Set; Key : Key_Type) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Find} (Container : Set; Key : Key_Type) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Floor} (Container : Set; Item : Key_Type) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Ceiling} (Container : Set; Item : Key_Type) @key{return} Cursor;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Key} (Position : Cursor) @key{return} Key_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} @AdaSubDefn{Element} (Container : Set; Key : Key_Type) @key{return} Element_Type;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Replace} (Container : @key{in out} Set; Key : @key{in} Key_Type; New_Item : @key{in} Element_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Delete} (Container : @key{in out} Set; Key : @key{in} Key_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Exclude} (Container : @key{in out} Set; Key : @key{in} Key_Type);]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "<" (Left : Cursor; Right : Key_Type) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} ">" (Left : Cursor; Right : Key_Type) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} "<" (Left : Key_Type; Right : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{function} ">" (Left : Key_Type; Right : Cursor) @key{return} Boolean;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{procedure} @AdaSubDefn{Update_Element_Preserving_Key} (Container : @key{in out} Set; Position : @key{in} Cursor; Process : @key{not null access procedure} (Element : @key{in out} Element_Type));]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ @key{end} Generic_Keys;]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{private}]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[ ... -- @RI[not specified by the language]]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{end} Ada.Containers.Ordered_Sets;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Two elements @i and @i are @i if both @i < @i and @i < @i return False, using the generic formal "<" operator for elements.@Defn2{Term=[equivalent element],Sec=[of a ordered set]}]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[Functions "<" and "=" on Element_Type values are expected to return the same result value each time they are called with a particular pair of element values. If @i = @i returns True, then @i = @i is expected to also return True. If @i < @i returns True, then @i < @i is expected to return False. For any two equivalent elements, "=" is expected to return True. If "<" or "=" behaves in some other manner, the behavior of this package is unspecified. Which subprograms of this package call "<" and "=", and how many times these functions are called, is unspecified.@PDefn{unspecified}]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[If the value of an element stored in a set is changed other than by an operation in this package such that at least one of "<" or "=" give different results, the behavior of this package is unspecified.@PDefn{unspecified}]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[See @RefSec{The Package Containers.Ordered_Maps} for a suggested implementation, and for justification of the restrictions regarding "<" and "=". Note that sets only need to store elements, not key/element pairs.]} @end{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn2{Term=[first element],Sec=[of a ordered set]} @Defn2{Term=[last element],Sec=[of a ordered set]} @Defn2{Term=[successor element],Sec=[of a ordered set]} The first element of a nonempty set is the one which is less than all the other elements in the set. The last element of a nonempty set is the one which is greater than all the other elements in the set. The successor of an element is the smallest element that is larger than the given element. The predecessor of an element is the largest element that is smaller than the given element. All comparisons are done using the generic formal "<" operator for elements.]} @begin{DescribeCode} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Delete_First (Container : @key{in out} Set);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Container is empty, Delete_First has no effect. Otherwise the element designated by First (Container) is removed from Container. Delete_First tampers with the cursors of Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Delete_Last (Container : @key{in out} Set);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Container is empty, Delete_Last has no effect. Otherwise the element designated by Last (Container) is removed from Container. Delete_Last tampers with the cursors of Container.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Floor (Container : Set; Item : Element_Type) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Floor searches for the last element which is not greater than Item. If such an element is found, a cursor that designates it is returned. Otherwise No_Element is returned.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Ceiling (Container : Set; Item : Element_Type) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Ceiling searches for the first element which is not less than Item. If such an element is found, a cursor that designates it is returned. Otherwise No_Element is returned.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} First_Element (Container : Set) @key{return} Element_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Element (First (Container)).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Last (Container : Set) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Returns a cursor that designates the last node in Container. If Container is empty, returns No_Element.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Last_Element (Container : Set) @key{return} Element_Type;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Element (Last (Container)).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} Previous (Position : Cursor) @key{return} Cursor;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[If Position equals No_Element, then Previous returns No_Element. Otherwise Previous returns a cursor designating the element that precedes the one designated by Position. If Position designates the first element, then Previous returns No_Element.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Previous (Position : @key{in out} Cursor);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Position := Previous (Position).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} "<" (Left, Right : Cursor) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Element (Left) < Element (Right).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} ">" (Left, Right : Cursor) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Element (Right) < Element (Left).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} "<" (Left : Cursor; Right : Element_Type) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Element (Left) < Right.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} ">" (Left : Cursor; Right : Element_Type) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Right < Element (Left).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} "<" (Left : Element_Type; Right : Cursor) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Left < Element (Right).]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{function} ">" (Left : Element_Type; Right : Cursor) @key{return} Boolean;]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Equivalent to Element (Right) < Left.]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],KeepNext=[T],Text=[@key{procedure} Reverse_Iterate (Container : @key{in} Set; Process : @key{not null access procedure} (Position : @key{in} Cursor));]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Trailing],Text=[Iterates over the elements in Container as per Iterate, with the difference that the elements are traversed in predecessor order, starting with the last node.]} @end{DescribeCode} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[ For any two elements @i and @i, the boolean values (@i < @i), (Key(@i) < @i), and (Key(@i) > @i) are all expected to be equal. If Key, Generic_Keys."<", or Generic_Keys.">" behave in some other manner, the behavior of this package is unspecified. Which subprograms of this package call Key, Generic_Keys."<" and Generic_Keys.">", and how many times the functions are called, is unspecified.@PDefn{unspecified}]} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[In addition to the semantics described in @RefSecNum{Sets}, the subprograms in package Generic_Keys named Floor, Ceiling, "<", and ">", are equivalent to the corresponding subprograms in the parent package, with the difference that the Key subprogram parameter is compared to elements in the container using the Generic_Keys generic formal relational operators.]} @end{StaticSem} @begin{ImplAdvice} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[If @i is the length of a set, then the worst-case time complexity of the Insert, Include, Replace, Delete, Exclude and Find operations that take an element parameter should be O((log @i)**2) or better. The worst-case time complexity of the subprograms that take a cursor parameter should be O(1).]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[The worst-case time complexity of the Insert, Include, Replace, Delete, Exclude and Find operations of Containers.Ordered_Sets that take an element parameter should be O((log @i)**2). The worst-case time complexity of the subprograms of Containers.Ordered_Sets that take a cursor parameter should be O(1).]}]} @end{ImplAdvice} @begin{ImplNote} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[See @RefSec{The Package Containers.Ordered_Maps} for implementation notes regarding some of the operations of this package.]} @end{ImplNote} @begin{Extend95} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn{extensions to Ada 95} The generic package Ada.Containers.Ordered_Sets is new.]} @end{Extend95} @LabeledAddedSubclause{Version=[2],Name=[The Package Containers.Indefinite_Vectors]} @begin{Intro} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The language-defined generic package Containers.Indefinite_Vectors provides a private type Vector and a set of operations. It provides the same operations as the package Containers.Vectors (see @RefSecNum{The Package Containers.Vectors}) does, with the difference that the generic formal Element_Type is indefinite.]} @end{Intro} @begin{StaticSem} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[The declaration of the generic library package Containers.Indefinite_Vectors@ChildUnit{Parent=[Ada.Containers],Child=[Indefinite_Vectors]} has the same contents as Containers.Vectors except:]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The generic formal Element_Type is indefinite.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The Element parameter of access subprogram Process of Update_Element may be constrained even if Element_Type is unconstrained.]} @end{Itemize} @end{StaticSem} @begin{Extend95} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn{extensions to Ada 95} The generic package Ada.Containers.Indefinite_Vectors is new.]} @end{Extend95} @LabeledAddedSubclause{Version=[2],Name=[The Package Containers.Indefinite_Doubly_Linked_Lists]} @begin{Intro} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The language-defined generic package Containers.Indefinite_Doubly_Linked_Lists provides private types List and Cursor, and a set of operations for each type. It provides the same operations as the package Containers.Doubly_Linked_Lists (see @RefSecNum{The Package Containers.Doubly_Linked_Lists}) does, with the difference that the generic formal Element_Type is indefinite.]} @end{Intro} @begin{StaticSem} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[The declaration of the generic library package Containers.Indefinite_Doubly_Linked_Lists@ChildUnit{Parent=[Ada.Containers],Child=[Indefinite_Doubly_Linked_Lists]} has the same contents as Containers.Doubly_Linked_Lists except:]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The generic formal Element_Type is indefinite.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Keepnext=[T],Type=[Leading],Text=[The procedure with the profile:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Noprefix=[T],Keepnext=[T],Type=[Leading],Text=[@key{procedure} Insert (Container : @key{in out} List; Before : @key{in} Cursor; Position : @key{out} Cursor; Count : @key{in} Count_Type := 1);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Noprefix=[T],Text=[is omitted.]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This procedure is omitted because there is no way to create a default-initialized object of an indefinite type. We considered having this routine insert an empty element similar to the empty elements of a vector, but rejected this possibility because the semantics are fairly complex and very different from the existing case. That would make it more error-prone to convert a container from a definite type to an indefinite type; by omitting the routine completely, any problems will be diagnosed by the compiler.]} @end{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The Element parameter of access subprogram Process of Update_Element may be constrained even if Element_Type is unconstrained.]} @end{Itemize} @end{StaticSem} @begin{Extend95} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn{extensions to Ada 95} The generic package Ada.Containers.Indefinite_Doubly_Linked_Lists is new.]} @end{Extend95} @LabeledAddedSubclause{Version=[2],Name=[The Package Containers.Indefinite_Hashed_Maps]} @begin{Intro} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The language-defined generic package Containers.Indefinite_Hashed_Maps provides a map with the same operations as the package Containers.Hashed_Maps (see @RefSecNum{The Package Containers.Hashed_Maps}), with the difference that the generic formal types Key_Type and Element_Type are indefinite.]} @end{Intro} @begin{StaticSem} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[The declaration of the generic library package Containers.Indefinite_Hashed_Maps@ChildUnit{Parent=[Ada.Containers],Child=[Indefinite_Hashed_Maps]} has the same contents as Containers.Hashed_Maps except:]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The generic formal Key_Type is indefinite.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The generic formal Element_Type is indefinite.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Keepnext=[T],Type=[Leading],Text=[The procedure with the profile:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Noprefix=[T],Keepnext=[T],Type=[Leading],Text=[@key{procedure} Insert (Container : @key{in out} Map; Key : @key{in} Key_Type; Position : @key{out} Cursor; Inserted : @key{out} Boolean);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Noprefix=[T],Text=[is omitted.]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This procedure is omitted because there is no way to create a default-initialized object of an indefinite type. We considered having this routine insert an empty element similar to the empty elements of a vector, but rejected this possibility because the semantics are fairly complex and very different from the existing case. That would make it more error-prone to convert a container from a definite type to an indefinite type; by omitting the routine completely, any problems will be diagnosed by the compiler.]} @end{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The Element parameter of access subprogram Process of Update_Element may be constrained even if Element_Type is unconstrained.]} @end{Itemize} @end{StaticSem} @begin{Extend95} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn{extensions to Ada 95} The generic package Ada.Containers.Indefinite_Hashed_Maps is new.]} @end{Extend95} @LabeledAddedSubclause{Version=[2],Name=[The Package Containers.Indefinite_Ordered_Maps]} @begin{Intro} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The language-defined generic package Containers.Indefinite_Ordered_Maps provides a map with the same operations as the package Containers.Ordered_Maps (see @RefSecNum{The Package Containers.Ordered_Maps}), with the difference that the generic formal types Key_Type and Element_Type are indefinite.]} @end{Intro} @begin{StaticSem} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[The declaration of the generic library package Containers.Indefinite_Ordered_Maps@ChildUnit{Parent=[Ada.Containers],Child=[Indefinite_Ordered_Maps]} has the same contents as Containers.Ordered_Maps except:]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The generic formal Key_Type is indefinite.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The generic formal Element_Type is indefinite.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Keepnext=[T],Type=[Leading],Text=[The procedure with the profile:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Noprefix=[T],Keepnext=[T],Type=[Leading],Text=[@key{procedure} Insert (Container : @key{in out} Map; Key : @key{in} Key_Type; Position : @key{out} Cursor; Inserted : @key{out} Boolean);]} @end{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Noprefix=[T],Text=[is omitted.]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This procedure is omitted because there is no way to create a default-initialized object of an indefinite type. We considered having this routine insert an empty element similar to the empty elements of a vector, but rejected this possibility because the semantics are fairly complex and very different from the existing case. That would make it more error-prone to convert a container from a definite type to an indefinite type; by omitting the routine completely, any problems will be diagnosed by the compiler.]} @end{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The Element parameter of access subprogram Process of Update_Element may be constrained even if Element_Type is unconstrained.]} @end{Itemize} @end{StaticSem} @begin{Extend95} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn{extensions to Ada 95} The generic package Ada.Containers.Indefinite_Ordered_Maps is new.]} @end{Extend95} @LabeledAddedSubclause{Version=[2],Name=[The Package Containers.Indefinite_Hashed_Sets]} @begin{Intro} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The language-defined generic package Containers.Indefinite_Hashed_Sets provides a set with the same operations as the package Containers.Hashed_Sets (see @RefSecNum{The Package Containers.Hashed_Sets}), with the difference that the generic formal type Element_Type is indefinite.]} @end{Intro} @begin{StaticSem} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[The declaration of the generic library package Containers.Indefinite_Hashed_Sets@ChildUnit{Parent=[Ada.Containers],Child=[Indefinite_Hashed_Sets]} has the same contents as Containers.Hashed_Sets except:]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The generic formal Element_Type is indefinite.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The Element parameter of access subprogram Process of Update_Element_Preserving_Key may be constrained even if Element_Type is unconstrained.]} @end{Itemize} @end{StaticSem} @begin{Extend95} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn{extensions to Ada 95} The generic package Ada.Containers.Indefinite_Hashed_Sets is new.]} @end{Extend95} @LabeledAddedSubclause{Version=[2],Name=[The Package Containers.Indefinite_Ordered_Sets]} @begin{Intro} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The language-defined generic package Containers.Indefinite_Ordered_Sets provides a set with the same operations as the package Containers.Ordered_Sets (see @RefSecNum{The Package Containers.Ordered_Sets}), with the difference that the generic formal type Element_Type is indefinite.]} @end{Intro} @begin{StaticSem} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Type=[Leading],Text=[ Containers.Indefinite_Ordered_Sets@ChildUnit{Parent=[Ada.Containers],Child=[Indefinite_Ordered_Sets]} has the same contents as Containers.Ordered_Sets except:]} @begin{Itemize} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The generic formal Element_Type is indefinite.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The Element parameter of access subprogram Process of Update_Element_Preserving_Key may be constrained even if Element_Type is unconstrained.]} @end{Itemize} @end{StaticSem} @begin{Extend95} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn{extensions to Ada 95} The generic package Ada.Containers.Indefinite_Ordered_Sets is new.]} @end{Extend95} @LabeledAddedSubclause{Version=[2],Name=[Array Sorting]} @begin{Intro} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[The language-defined generic procedures Containers.Generic_Array_Sort and Containers.Generic_Constrained_Array_Sort provide sorting on arbitrary array types.]} @end{Intro} @begin{StaticSem} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],KeepNext=[T],Type=[Leading],Text=[The generic library procedure Containers.Generic_Array_Sort has the following declaration:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{generic} @key{type} Index_Type @key{is} (<>); @key{type} Element_Type @key{is private}; @key{type} Array_Type @key{is array} (Index_Type @key{range} <>) @key{of} Element_Type; @key{with function} "<" (Left, Right : Element_Type) @key{return} Boolean @key{is} <>; @key{procedure} Ada.Containers.Generic_Array_Sort (Container : @key{in out} Array_Type);@ChildUnit{Parent=[Ada.Containers],Child=[Generic_Array_Sort]} @key{pragma} Pure (Ada.Containers.Generic_Array_Sort);]} @end{Example} @begin{DescribeCode} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Reorders the elements of Container such that the elements are sorted smallest first as determined by the generic formal "<" operator provided. Any exception raised during evaluation of "<" is propagated.]} @begin{Ramification} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[This implies swapping the elements, usually including an intermediate copy. This of course means that the elements will be copied. Since the elements are non-limited, this usually will not be a problem. Note that there is Implementation Advice below that the implementation should use a sort that minimizes copying of elements.]} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[The sort is not required to be stable (and the fast algorithm required will not be stable). If a stable sort is needed, the user can include the original location of the element as an extra "sort key". We considered requiring the implementation to do that, but it is mostly extra overhead -- usually there is something already in the element that provides the needed stability.]} @end{Ramification} @end{DescribeCode} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],KeepNext=[T],Type=[Leading],Text=[The generic library procedure Containers.Generic_@!Constrained_@!Array_Sort has the following declaration:]} @begin{Example} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[@key{generic} @key{type} Index_Type @key{is} (<>); @key{type} Element_Type @key{is private}; @key{type} Array_Type @key{is array} (Index_Type) @key{of} Element_Type; @key{with function} "<" (Left, Right : Element_Type) @key{return} Boolean @key{is} <>; @key{procedure} Ada.Containers.Generic_Constrained_Array_Sort@ChildUnit{Parent=[Ada.Containers],Child=[Generic_Constrained_Array_Sort]} (Container : @key{in out} Array_Type); @key{pragma} Pure (Ada.Containers.Generic_Constrained_Array_Sort);]} @end{Example} @begin{DescribeCode} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[Reorders the elements of Container such that the elements are sorted smallest first as determined by the generic formal "<" operator provided. Any exception raised during evaluation of "<" is propagated.]} @end{DescribeCode} @end{StaticSem} @begin{ImplAdvice} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[ The worst-case time complexity of a call on an instantiation of Containers.Generic_Array_Sort or Containers.Generic_Constrained_Array_Sort should be O(@i**2) or better, and the average time complexity should be better than O(@i**2), where @i is the length of the Container parameter.]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[Containers.Generic_Array_Sort and Containers.Generic_Constrained_Array_Sort should have an average time complexity better than O(@i{N}**2) and worst case no worse than O(@i{N}**2).]}]} @begin{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[In other words, we're requiring the use of a sorting algorithm better than O(@i**2), such as Quicksort. No bubble sorts allowed!]} @end{Discussion} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[ Containers.Generic_Array_Sort and Containers.Generic_Constrained_Array_Sort should minimize copying of elements.]} @ChgImplAdvice{Version=[2],Kind=[AddedNormal],Text=[@ChgAdded{Version=[2], Text=[Containers.Generic_Array_Sort and Containers.Generic_Constrained_Array_Sort should minimize copying of elements.]}]} @begin{Honest} @ChgRef{Version=[2],Kind=[AddedNormal]} @ChgAdded{Version=[2],Text=[We do not mean @lquotes@;absolutely minimize@rquotes@; here; we're not intending to require a single copy for each element. Rather, we want to suggest that the sorting algorithm chosen is one that does not copy items unnecessarily. Bubble sort would not meet this advice, for instance.]} @end{Honest} @end{ImplAdvice} @begin{Extend95} @ChgRef{Version=[2],Kind=[AddedNormal],ARef=[AI95-00302-03]} @ChgAdded{Version=[2],Text=[@Defn{extensions to Ada 95} The generic packages Ada.Containers.Generic_Array_Sort and Ada.Containers.Generic_Constrained_Array_Sort are new.]} @end{Extend95}