fix(export): a transition owns its source member and parameters; chained ends stay chains (#803)

[someshSandbox]

Fixes #803.

package P {
    item def Sig;
    state def S {
        entry;
        then a;
        state a;
        state b {
            entry;
            then c;
            state c;
        }
        transition t first a then b.c;
        transition u first a accept Sig then b;
        transition v first b.c then a;
    }
}

TransitionUsage owns	develop	this PR
the source (FeatureChainMember)	nothing; only the derived source	first, a Membership whose memberElement is a, or for first b.c an OwningMembership owning a chain Feature (b, c)
EmptyParameterMembers	none	one, then a second ahead of a trigger (u): each a ParameterMembership owning an undeclared ReferenceUsage
the target end of then b.c	ReferenceSubsetting to b::c	ReferenceSubsetting owning a chain Feature (b, c)
read back from the graph alone	first c then a, first a then c	as written

Grammar (SysML-textual-bnf):

• TransitionUsage: ownedRelationship += FeatureChainMember, then EmptyParameterMember, then (EmptyParameterMember TriggerActionMember)? (:1281-1290). TargetTransitionUsage likewise (:1292-1300).
• FeatureChainMember : Membership = memberElement = [QualifiedName] | OwnedFeatureChainMember (:1111-1116).
• EmptyParameterMember (:1081-1085).
• OwnedReferenceSubsetting … | referencedFeature = OwnedFeatureChain (:463-466).

The order of the owned relationships follows the grammar: source, parameter(s), trigger, guard, effect, succession, body.

Change:

• Export (behavior.go):
  • transitionHeadMembers writes the source member and the empty parameters ahead of the trigger.
  • The parameters are minted as elements (_linkparam, _triggerparam), as the succession is, so the element form reads them back as members.
  • transitionSuccession passes a chained target through connectorEnd's chain path, the way succession first a then b.c already writes one.
  • The derived source/target are unchanged.
• Reader:
  • transitionImplied already treats a source Membership and an in parameter as implied. It now also accepts the chain Feature a first b.c member owns.
  • It compares a chained source or target with the head by the chain's last link (chainTail).
  • verifyReferentMembership accepts a transition's source Membership when it names the transition's sysml:source, and refuses it otherwise.
  • transitionChainText writes a chained source or target as its chain, so it is no longer collapsed to the last link.
  • In the element form, deriveTransitionHeads derives the source and target from the source chain and a chained end. bodiedOwners leaves out the head members, and an unstated parameter direction counts as in.
• rdf-mapping.md describes the new members.

Tests:

• tests/export/transition_succession_test.go:TestTransitionOwnsItsSourceParameterAndChainedEnds:

  • the notation back from the graph alone;
  • in the API JSON, for t, u and v: the leading owned relationships' metaclasses, the source member or chain, the empty parameters, and the target end or chain; the JSON reads back;
  • a source member naming another state than sysml:source is refused.

  It fails on develop. The model validates cleanly.

• TestTransitionStructureAloneReadsBack covers a graph in the API element form. With the transitions' source/target removed, the source member, source chain and chained target end state the heads. The test runs it again with the chains given only by their chainingFeature lists. A transition with a trigger does not read from the element form on develop either, so the test leaves it out.

• TestTransitionChainEndpointsCompareByTheirLinks: a head that states a chain must match the structural chain link by link. a1.c and a2.c both reach T::c, and restating one transition's head as the other's chain is refused for the source and the target.

• TestTransitionSuccessionFollowsEffectAndPrecedesBody now expects the source member and parameter ahead of the guard. TestMachineEndpointsLinkAcrossRegionsAndNesting expects the order annotations that now follow a transition's sysml:target.

• Seven .golden.ttl files are regenerated: end_binding_bodies, endpoint_scopes, imported_references, irregular_layout, shadowing_parameters, state_machine and then_after_members. Parsed as triple sets, no triple is lost; every file only gains the new members, chains and order annotations.

• internal/translate/..., tests/export/..., tests/corpus/..., tests/identity/..., tests/reposync/..., tests/grpc/..., internal/frontend/grpc/..., internal/workspace/..., internal/check/..., internal/exec/runtime/..., internal/syntax/... and internal/semantic/... pass.

The branch is based on a29c3e0a5, since develop at 76599c28e did not build (fixed since by #800). It merges cleanly with develop and touches nothing in migrate.

🤖 Generated with Claude Code

[HuiJun]

Thanks for this! Accepted