Overview of Ada 2022
7.4 Index parameters in array aggregates
in array aggregates (AI12-0061)
adds an optional index
in array aggregates (see RM
subtype Index is Positive range 1 .. 10;
type Array_Type is array (Index) of Positive;
Squares_Array : Array_Type := (for I in Index => I * I);
This provides a means of creating an aggregate when
the element type is limited, provides a better means of initialising
an array with a type invariant, and should be useful for everyday programming.
While these associations look like an iterator association
in an array aggregate (see 4.7), they actually are closely related to
normal named associations, with the same usage rules. Thus, multiple
associations are allowed (so long as all of the choices are static),
with or without index parameters in those other associations. Similarly,
the usual completeness checks apply to an aggregate with these associations.
Since these associations are not iterators, they do not allow iterator
filters (see 4.6
), as filters would make
the completeness checks impossible.
© 2021, 2022 Jeff Cousins