CVS difference for ais/ai-00254.txt

Differences between 1.15 and version 1.16
Log of other versions for file ais/ai-00254.txt

--- ais/ai-00254.txt	2004/11/14 06:37:00	1.15
+++ ais/ai-00254.txt	2004/11/17 00:52:48	1.16
@@ -3,6 +3,7 @@
 !standard  3.7    (09)
 !standard  3.10.2 (13)
 !standard  3.10.2 (32)
+!standard  3.10.2 (37)
 !standard  4.9.1  (02)
 !standard  6.1    (24)
 !standard  6.1    (27)
@@ -191,6 +192,15 @@
   of S shall be either a nonformal type declared within the generic unit or
   an anonymous access type of an access parameter.
 
+Replace the note 3.10.2(37) by:
+  The accessibility rules imply that it is possible to use the Access attribute
+  to implement "downward closures" -- that is, to pass a more-nested subprogram
+  as a parameter to a less-nested subprogram, as might be desired for example
+  for an iterator abstraction -- only for anonymous access-to-subprogram
+  parameters. Downward closures also can be implemented using generic formal
+  subprograms (see 12.6). Note that Unchecked_Access is not allowed for
+  subprograms.
+
 Replace 4.9.1(2) by
 
 A subtype statically matches another subtype of the same type if they have
@@ -965,6 +975,25 @@
 of @i<S> shall be either a nonformal type declared within the generic
 unit or an anonymous access type of an access parameter.>
 
+!corrigendum 03.10.02(37)
+
+@drepl
+@xindent<@s9<The accessibility rules imply that it is not possible to use the
+Access attribute to implement "downward closures" -- that is, to pass a
+more-nested subprogram as a parameter to a less-nested subprogram, as might be
+desired for example for an iterator abstraction. Instead, downward closures can
+be implemented using generic formal subprograms (see 12.6). Note that
+Unchecked_Access is not allowed for subprograms.>>
+@dby
+@xindent<@s9<The accessibility rules imply that it is possible to use the
+Access attribute to implement "downward closures" -- that is, to pass a
+more-nested subprogram as a parameter to a less-nested subprogram, as might be
+desired for example for an iterator abstraction -- only for anonymous
+access-to-subprogram parameters. Downward closures also can be implemented
+using generic formal subprograms (see 12.6). Note that Unchecked_Access is not
+allowed for subprograms.>>
+
+
 !corrigendum 4.9.1(2)
 
 @drepl
@@ -1085,7 +1114,7 @@
 !reference RM9X-3.10.2(16);4.0
 !reference AARM-12.3(12.p,12.q);4.0
 !reference LSN-1042 on Accessibility Checks in Generics
-!from Bob Duff $Date: 2004/11/14 06:37:00 $ $Revision: 1.15 $
+!from Bob Duff $Date: 2004/11/17 00:52:48 $ $Revision: 1.16 $
 !discussion
 
 Two issues related to access types and the accessibility rules came
@@ -1498,7 +1527,7 @@
 !topic LSN on Accessibility Checks in Generics
 !key LSN-1042 on Accessibility Checks in Generics
 !reference MS-12;4.6
-!from Bob Duff $Date: 2004/11/14 06:37:00 $ $Revision: 1.15 $
+!from Bob Duff $Date: 2004/11/17 00:52:48 $ $Revision: 1.16 $
 !discussion
 
 This Language Study Note discusses accessibility checks, and their

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