feat(fuml): translate classes, structural features, signals and active-class behavior in the referee's emitter

[devin-ai-integration]

What and why

The fUML referee's emitter (tools/referee/fuml/emit.go) translated only the primitive-valued activities of the reference implementation's test models; nine expressible activities stayed not-expressible with a not yet translated: reason because they create objects, write structural features, accept signals or run a class's behavior. This PR grows the emitter over those constructs — classes and structural features, signals, active classes — one rule per construct with its SysML v2 spelling recorded in docs/project/fuml-referee.md, extends the referee so object-valued inputs and outputs execute and compare, and gives the runtime what the rules need: an accepted signal flowing on from the accept's result pin, and a declared behavior started on an explicit perform.

Classes, object creation, structural features

• fUML Class → part def, generals as :> supertypes, each attribute at its exact declared multiplicity ([0..*] ordered nonunique, [0..3], …; the UML default [1..1] unwritten). A redefining property replaces the one it redefines; classifiers resolve by ID first and only then by name, and external type references never resolve to local classifiers.
• CreateObjectAction → action N { out result : T = new T(); }. Creation starts no behavior; StartObjectBehaviorAction does (below).
• ReadStructuralFeatureAction → out result … = object.f; at the feature's multiplicity.
• AddStructuralFeatureValueAction / RemoveStructuralFeatureValueAction / ClearStructuralFeatureAction → assign object.f := …; with the reference implementation's semantics: a replacing add or a single-valued feature takes the value; a unique feature drops its old copy; an unpositioned add inserts first (the reference's FirstChoiceStrategy), insertAt inserts at that one-based position with * appending and 0 out of range; a remove drops every copy (isRemoveDuplicates), the copy at removeAt, or the first copy; clear empties. The object flows on through the result pin.
• Untyped parameters (the reference runs them as String) are declared without a type; an inout parameter's input and output nodes are told apart by their edges.
• The referee (tools/referee/fuml/run.go, render.go) materializes class-typed inputs the way the reference's Environment.makeValue does (an object per class, features defaulted recursively) and renders object outputs by class and feature values, numbered by graph refinement rather than arrival order so identical objects compare by reference structure; a feature read that fails is a run error, not text.

Signals

• fUML Signal → attribute def with its attributes, specializing its generals, declared before the classes and activities of the closure; a class-typed signal attribute references its class.
• SendSignalAction → an action sending new <Signal>(…) to the object at its target pin, one argument pin per attribute, inherited ones included.
• AcceptEventAction of one SignalEvent → an accept node whose result pin is the instance received; an untyped result pin takes the trigger's signal type; a specialized signal satisfies an accept of its general through the runtime's conformance matching.
• Runtime: the lowering (internal/ir/lower/action_graph.go) records an accept's payload as the node's output feature, and the executor (internal/exec/runtime/action_executor.go) binds the accepted value on the accept's own performance, so flow receiver.msg to consumer.value carries the instance on. An accept whose trigger is a when/at/after condition has no payload and declares no output.

Active classes

• A class's owned behavior → an action def nested in its part def; its classifier behavior → the member action classifierBehavior : <Behavior>;, a declaration no creation starts. ReadSelfAction in such a behavior → this; at the top level of an activity performed on its own it stays a typed TranslateError (self there is the performance, not an object).
• An activity instantiated as an object (TestSpecializedSignalSend creates and starts TestSignalReceiver) → a part def of the activity's name around an action def of its body, when the body's shape is representable; a call of a class's owned behavior stays a typed TranslateError.
• StartObjectBehaviorAction → action N { in object : T; perform object.classifierBehavior.start; }, the classifier behavior found on the object's class or inherited from a general; a start passing arguments, of an object of a class without classifier behavior, or without an object pin is a typed TranslateError.
• An owned behavior's row is refereed through the top-level activities whose run starts an object of its owner — the activity holding the start and every activity calling it, transitively, of which those the record executes carry the row (ActiveClassBehavior through ActiveClassBehaviorSender) — fail when one fails, else pass when one passes, each reason naming the starter and, when the start is reached through a call, the activity holding it.
• Runtime: perform obj.beh.start; lowers to a start effect (lower.EffectStart) only where the operand, resolved through the scope tree, is a behavior the object holds or a feature declaring no start of its own — an action a part def declares as action start : Launch; is performed as any other feature — and the effect is what internal/exec/runtime/start_behavior.go runs as the object's own execution — this the object, its writes on the object's features, a message sent afterwards waking an accept it parks at, the object outliving the behavior's completion. Object behaviors are drained after the enclosing top-level action completes, so a sender's signals reach a behavior it started in the same run. A second start of a running behavior starts nothing more; a start on no one object or of a member that is no behavior of the object is a typed error; a start that fails is undone whole — its own work: an older parked behavior a message of the started one wakes is drained only once the start is kept, within a run boundary as a store's, so its move is never inside the start's undo; the trace records the start as the object's execution. A performed action that names no separate body (perform action a { … }) keeps resolving to itself.

Runtime fixes the referee surfaced

• Two flows out of one pin deliver twice. A value a streaming flow carries to a target not yet under way waits at the target's pin, keyed until now by source performance and pin alone, so the two flow Action_A.result to Action_B.input; routes of a fUML fork duplicating a token collapsed into one delivery and the second performance of the nested Copier ran with its required input unbound. Each flow declaration is a transfer of its own: internal/exec/runtime/action_frame.go stage keys the waiting place by source performance, pin and flow declaration (held images carry the flow), and internal/exec/smt/encode.go stagedSlot keys the encoding's slot the same way, so a later write along the same flow still replaces its earlier one while two flows each stage the write. action_flow_streaming_aliased_source_pin (a pin named by its inherited and its redefining name, two flows) states the contract and expects two deliveries; action_flow_streaming_two_flows_one_pin_to_call and stream_stage_test.go lock the fork shape. ForkMergeData reaches its recorded 0, 0 again; it stays differs-by-design for per-token re-firing alone. Fragment changes/unreleased/streaming-flow-per-declaration-transfer.fixed.md; the streaming-flow row of spec-compliance.md carries the rule.
• Object-typed parameters are referential; a port's directed feature is not. Materializing an occurrence gives a behavior's object-typed parameter no object of its own (an object flows into it), which is what lets a started behavior's in parameter bind to the object it is performed on. semantics.IsBehaviorParameter restricts this to parameters a behavior or step owns, so a port definition's in item cmd : Cmd; keeps its composite value and an exhibited state machine's parameter binds from engineControl.cmd (exhibited_state_self_target).

Not translated

An edge weight other than 1 and an object-flow cycle through control nodes remain typed translation refusals naming the edge; no activity of the pinned suite has either (all 439 test-model and 93 exception-model weights are 1), so no row depends on them. TestSignalReceiver stays not-expressible: it reads self as a top-level activity performed on its own.

Referee

./scripts/download-fuml-suite.sh && go run -C tools ./cmd/fuml-referee -jobs 8:

bucket	before	after
pass	15	23
fail	0	0
not-expressible	36	28
differs-by-design	4	4

Moved to pass: TestGeneralizationAssembly, TestClassObjectCreator, TestClassWriterReader, TestClassAttributeWriter, TestClassAttributeValueRemover (objects and structural features); TestSpecializedSignalSend, ActiveClassBehaviorSender, ActiveClassBehavior (signals and active classes). Every moved row is adjudicated in docs/project/fuml-referee.md; the classifier's 27 rows did not move; the fixed expected record for ActiveClassBehavior (skipped, runs only as part of its owner) is unchanged. The baseline's pin — tag v1.5.0a, commit 45e50633…, the four digests — is unchanged; only its develop provenance advanced with the merge of develop.

Specification basis

fUML 1.5 (formal/2021-07-01) § 8.6 Actions — CreateObjectAction, ReadSelfAction, the structural feature actions, SendSignalAction, AcceptEventAction, StartObjectBehaviorAction — and § 8.8 object-behavior startup (creation starts nothing; an explicit start does), as the pinned reference implementation (v1.5.0a) executes them. docs/project/spec-compliance.md: the fUML referee row carries the counts above, and a new row records the declared-behavior start (passive construction, explicit perform obj.beh.start;, this, message wake-up, owner preservation, duplicate start, inherited behavior, typed failures, rollback, trace). docs/internals/design/precise-semantics-alignment.md states the same lifecycle.

How it was verified

• tools/referee/fuml/emit_test.go: TestEmitClasses, TestEmitObjectCreationAndFeatureWrites, TestEmitFeatureReads, TestEmitReadSelf, TestEmitActivityAsObject, TestExecuteStartedObject, TestExecuteObjects, TestExecuteUnorderedObjects, TestExecuteIdenticalObjectsNumberByReference, TestEmitSignals, TestEmitRedefinedProperties, TestEmitSignalTypedAttribute, TestEmitClassTypedSignalAttribute, TestEmitPrimitiveNamesakeAndPositionedScalarRemove, TestEmitExternalTypesNeverLocalClassifiers, TestEmitIDReferencesNeverResolveByName, TestExecuteInsertAtZeroIsOutOfRange, TestEmitSendSignal, TestEmitAcceptEvent, TestRenderSignalValues, TestRenderNumbersObjectsByStructureNotArrival, TestExecuteSignals, TestEmitRefusesWeightsAndCycles on hand-built models; every emitted model passes Validate. referee_test.go: TestRefereeOwnedBehavior, TestRefereeOwnedBehaviorStartedThroughACall.
• internal/ir/lower: TestPerformOfStartLowersToStartEffect, TestPerformOfBehaviorStaysPerform, TestPerformOfDeclaredStartActionStaysPerform, TestAcceptNodePayloadIsItsOutputPin.
• internal/exec/runtime: TestRuntimeRobustnessClassifierBehaviorStart (passive construction, start as the object, wake by a later message, second start, inherited behavior, start on no object, start of no behavior, an action declared as start performed rather than started, failing start undone, trace), TestStartedActionAwaitingAMessageIsWokenByASibling, TestRuntimeRobustnessAcceptPayload, conformance pairs accept_payload_flows_from_pin, action_flow_streaming_two_flows_one_pin_to_call, action_flow_streaming_aliased_source_pin (two deliveries), stream_stage_test.go:TestStagedStreams (same-flow replacement, distinct flows side by side); internal/semantic/semantics/shape_test.go:TestIsBehaviorParameter.
• go build ./..., go vet ./..., gofmt -l . (empty), go test ./... (root and tools/), make lint, make docs-check, python3 scripts/changelog.py check, mkdocs build --strict — all clean on the merged head.
• OPENSYSML_REQUIRE_TRAINING_CORPUS=1 OPENSYSML_REQUIRE_PILOT_CORPORA=1 go test -count=1 ./tests/corpus -run 'TestTrainingExamples|TestPilotCorpora' clean.
• go run -C tools ./cmd/fuml-referee -jobs 8 -check clean; -json twice byte-identical.

Checklist

• make test and make lint pass locally
• Tests added or updated for the change
• Documentation extended where it already covers the surface (see CONTRIBUTING.md)
• Changelog entry added as changes/unreleased/<slug>.<section>.md, not as an edit to CHANGELOG.md
• baselines regenerated and make docs-counts run if a gate count moved (compliance rows need nothing: the census is counted at docs build)
• No internal work-item labels (waves, slices, F4, K5) in the body, docs, or changelog

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR. Add '(aside)' to your comment to have me ignore it.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

• Disable automatic comment, CI, and merge conflict monitoring

[devin-ai-integration]

Devin Review found 1 new potential issue.