Version 1.2 of ai12s/ai12-0183-1.txt

Unformatted version of ai12s/ai12-0183-1.txt version 1.2
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!standard D.4(4)          16-12-15 AI12-0183-1/02
!standard D.4(4)
!standard D.4(7/5)
!class presentation 16-03-23
!status Amendment 1-2012 16-03-23
!status work item 16-03-23
!status received 16-03-23
!priority Low
!difficulty Easy
!qualifier Omission
!subject Presentation errors in Ada 2012 post Corrigendum 1
!summary
This AI corrects minor errors in the Standard.
1) Add Ordered_FIFO_Queuing to D.4(4).
2) Be specific about which policy is defined in 9.5.3 and 9.7.1.
3) The header "Static Semantics" is missing from 4.9.
!question
1) AI12-0163-1 defines policy Ordered_FIFO_Queuing. But the Legality Rule D.4(4) does not allow that as a policy name. Should it? (Yes.)
2) D.5(7/2) says "The rules for this policy are specified in 9.5.3 and 9.7.1." This paragraph defines three queuing policies. "This" in this text refers to that last one mentioned (I think), but that's ambiguious. Should we be specific here? (Yes.)
3) 4.9 does not have a Static Semantics portion; the entire section though paragraph 32 is not under any header (which represents introductory text). Only paragraph 1 appears to be introductory, should there be a Static Semantics portion in this subclause? (Yes.)
!recommendation
(See Summary.)
!wording
[Editor's note: The following changes are included in the draft RM, even though it is not intended for the full ARG to take up this AI until just before the next document (a Revision?) is submitted to WG 9. This AI is only used to record wording changes that appear to the editor to be obvious improvements in the Standard.]
1) Modify D.4(4):
The policy_identifier shall be either FIFO_Queuing, {Ordered_FIFO_Queuing, }Priority_Queuing or an implementation-defined identifier.
2) Modify D.5(7/2) [as modified by AI12-0163]:
Three queuing policies, FIFO_Queuing, Ordered_FIFO_Queuing, and Priority_Queuing, are language defined. If no Queuing_Policy pragma applies to any of the program units comprising the partition, the queuing policy for that partition is FIFO_Queuing. The rules for {the FIFO_Queuing}[this] policy are specified in 9.5.3 and 9.7.1.
3) Add a "Static Semantics" header before 4.9(2).
!discussion
1) This is a clear omission from AI12-0163-1. Obviously, if we define a queuing policy, we have to allow it to be used in the Queuing_Policy pragma, else it would be the most useless Ada construct ever.
2) The other two queuing policies are defined in this subclause, so it's fairly obvious that "this" must refer to FIFO_Queuing. But it shouldn't be necessary to read the entire subclause in order to figure that out.
3) 4.9(2-32) are not introductory text, so they should be in some headed portion. Static Semantics seems appropriate for these rules.
!corrigendum 4.9(2)
Replace the paragraph:
A static expression is a scalar or string expression that is one of the following:
by:
Static Semantics
A static expression is a scalar or string expression that is one of the following:
!corrigendum D.4(4)
Replace the paragraph:
The policy_identifier shall be either FIFO_Queuing, Priority_Queuing or an implementation-defined identifier.
by:
The policy_identifier shall be either FIFO_Queuing, Ordered_FIFO_Queuing, Priority_Queuing or an implementation-defined identifier.
!corrigendum D.4(7/5)
Replace the paragraph:
Three queuing policies, FIFO_Queuing, Ordered_FIFO_Queuing, and Priority_Queuing, are language defined. If no Queuing_Policy pragma applies to any of the program units comprising the partition, the queuing policy for that partition is FIFO_Queuing. The rules for this policy are specified in 9.5.3 and 9.7.1.
by:
Three queuing policies, FIFO_Queuing, Ordered_FIFO_Queuing, and Priority_Queuing, are language defined. If no Queuing_Policy pragma applies to any of the program units comprising the partition, the queuing policy for that partition is FIFO_Queuing. The rules for the FIFO_Queuing policy are specified in 9.5.3 and 9.7.1.
!ASIS
No changes needed.
!ACATS test
No test needed.
!appendix

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