ST6RI-959 SysML 2.1 Ballot 3 - Abstract Syntax

[seidewitz]

This PR implements resolutions for issues that were approved on SysML 2.1 RTF Ballot 3 related to abstract syntax. These issue all had been pro-actively implemented, so changes for this PR are minimal.

Changes

• SYSML21-300 Constraint checkRequirementUsageSubrequirementSpecialization needs to exclude assumed requirements
  • Implemented since PR ST6RI-168 Concrete syntax for requirements #87, except that final RTF-approved resolution calls for excluding required constraints, too.
• SYSML21-302 Override namingFeature for a view RenderingUsage
  • Implemented since PR ST6RI-361 Update implementation for 2021-04 metamodel baseline #226. Updated in this PR to more thoroughly check for nulls.
• SYSML21-368 Abstract syntax changes from resolution of SYSML2_-159 were not made
  • Implemented since PR ST6RI-825 Send and accept action notation (SYSML2_-159) #626. No changes in this PR.

[himi]

@seidewitz Sorry for making you wait. I could not set up MgPy environment with this version and I tried to evaluate with %eval but I could not. For example, to test subrequirements, I used:

requirement r1 {
    require r2;
    assume r3;
    requirement r11;
}
requirement r2;
requirement r3;

and tried
%show r1 or %eval "r1.subrequirements". But none of them worked. It's implicit elements and probably I need to transformAll() to get such features. (I thought %show shows implicit elements as well). Anyway, I could not find any issues in the code and approve this PR.

[seidewitz]

@himi
Thanks.

and tried %show r1 or %eval "r1.subrequirements"

The problem with %show r1 is that a requirement usage is ultimately a kind of KerML expression, and %show does not expand expressions, in order to make the display of ASTs with complicated expressions tractable. This is a quirk that has needed to be fixed for a while!

The problem with %eval "r1.subrequirements" is that it requires "subsetting roll-up" to evaluate properly, and this is not currently implemented in the Pilot Implementation.

The best way to see that the code sets the implied relationships correctly is to use the outline in the Eclipse Xtext editor.