[Feature]: Function::isModelLevelEvaluable — generate the Kernel Functions Library membership set #364

Description

FunctionExtensions.ComputeIsModelLevelEvaluable(this IFunction) in
SysML2.NET/Extend/FunctionExtensions.cs:69 is a NotSupportedException stub. It has no OCL
derivation — per KerML 1.0 §8.3.4.7.4 (normative) it is a Kernel Functions Library membership
test:

Certain Functions from the Kernel Functions Library are considered to have
isModelLevelEvaluable = true. For all other Functions it is false.

The set is KerML 1.0 Table 5 (§8.2.5.8.1) + Table 7 (§8.2.5.8.2) — 39 operator symbols, 3 of them
marked No. Do not hardcode the names: 36 of the 39 rows are derivable from sources the code
generator already reads.

Derivation

1. Operator symbols from the grammar — Resources/KerML-textual-bnf.kebnf, token rules
   ConditionalBinaryOperator, BinaryOperator, UnaryOperator, ClassificationTestOperator,
   CastOperator, MetaclassificationTestOperator, MetaCastOperator, plus the inline
   operator = 'if' | 'all' | '[' | ',' assignments. → 35 symbols.
2. The 4 remaining operators from the XMI — IndexExpression, FeatureChainExpression,
   CollectExpression and SelectExpression do not assign operator in the grammar; it is an OCL
   constraint body in Resources/KerML_only_xmi.uml: operator = '#' (:5937), '.' (:5761),
   'collect' (:5692), 'select' (:5633). → 39 total.
3. Symbol → library function — from
   Resources/sysml.library.kpar/Kernel_Function_Library-1.0.0.kpar: the first package declaring a
   Function with that declaredName, probed in the order BaseFunctions, DataFunctions,
   ControlFunctions. That order is not invented — it is the OCL at
   Resources/KerML_only_xmi.uml:5671, already implemented at
   SysML2.NET/Extend/OperatorExpressionExtensions.cs:63. It resolves the == / === collision
   (both are declared in BaseFunctions and DataFunctions) to BaseFunctions, matching
   Table 5.
4. Subtract the 3 curated exclusions — the only No rows: BaseFunctions::'all' (type extent),
   BaseFunctions::'[' and DataFunctions::'~' (abstract, no default definition in the library; see
   the notes at Resources/KerML-textual-bnf.kebnf:1178 and :1064). isAbstract does not
   discriminate — BaseFunctions::'==' is abstract and is evaluable — so these three must be an
   explicit list with a spec citation each.

This derivation is deliberately narrower than "every Function in the three packages": max, min,
reduce, forAll, selectOne, minimize etc. are declared there but are not operator terminals,
and fall out automatically.

Generator must validate (fail generation on mismatch)

• Every derived qualified name resolves to a Function in the Kernel Function Library.
• Steps 1–3 yield exactly 39 symbols — any other count means spec or library drift.
• The exclusion list has 3 entries and every entry is present in the derived set.
• '^' and '**' are separate Function declarations in DataFunctions even though Table 5
  collapses them into one row; both belong in the emitted set.

Output

A frozen set of qualified names in an AutoGen file (alongside
SysML2.NET/LexicalRules/AutoGenLexicalRules/), consumed by ComputeIsModelLevelEvaluable via
functionSubject.qualifiedName. Scope is the evaluable set only — the full operator → function map
is #365's concern.

Notes

SysML2.NET.CodeGenerator/Grammar/ already carries the KEBNF object model (TerminalElement,
Alternatives, TextualNotationRule) and GrammarLoader, and UmlCoreLexicalRulesGenerator
already emits from this rule shape. Reading .kermlx is the one new capability —
SysML2.NET.CodeGenerator references uml4net.xmi only, not SysML2.NET.Serializer.Xmi.

Impact

Completes the runtime behaviour of
InvocationExpressionExtensions.ComputeRedefinedModelLevelEvaluableOperation
(SysML2.NET/Extend/InvocationExpressionExtensions.cs:57), which compiles today but throws through
function.isModelLevelEvaluable.

Checklist

• Generator: extract operator terminals from the KEBNF token rules
• Generator: extract the 4 XMI operator = '…' constraint operators
• Generator: read Kernel_Function_Library-1.0.0.kpar, map symbol → qualified name via the OCL probe order
• Generator: curated 3-entry exclusion list + the drift validations above
• Handlebars template + emitted AutoGen file
• bool ComputeIsModelLevelEvaluable(this IFunction)
• SysML2.NET.Tests/Extend/FunctionExtensionsTestFixture.cs

System Configuration

• SysML2.NET version: 0.19.0
• Source files:
  • SysML2.NET/Extend/FunctionExtensions.cs
  • SysML2.NET.CodeGenerator/Generators/UmlHandleBarsGenerators/