call method

Implementation

@override
Object? call(
  InterpreterVisitor visitor,
  List<Object?> positionalArguments, [
  Map<String, Object?> namedArguments = const {},
  List<RuntimeType>? typeArguments,
]) {
  // Establish `D4.activeVisitor` for the duration of every interpreted
  // function call. This makes the visitor available to any native code
  // path that the user function triggers — most importantly the
  // `InterpretedInstance.==` / `.hashCode` overrides, which dispatch
  // through the active visitor when native Dart collections
  // (`Map<UserCell, …>`, `Set<UserCell>`, …) look up keys. Without this
  // wrap, native container operations downstream of a `targetValue[key]`
  // (visitIndexExpression) read `D4.activeVisitor == null` and silently
  // fall back to identity hashing, breaking content-equality lookups.
  //
  // Hot path: push/pop the active visitor directly rather than via
  // `withActiveVisitor`, whose `T Function()` argument allocates a closure on
  // every interpreted function call. The save/set/restore semantics are
  // identical (nesting included).
  final previousActiveVisitor = D4.pushActiveVisitor(visitor);
  // The interpreted call stack (D4rtCallStack): an error leaving this call
  // is snapshotted against the stack as it stood when it was raised.
  final callStack = visitor.callStack;
  callStack.enter(_name ?? '<anonymous>');
  // Until the body's first statement runs, the frame is at the body — which
  // is all an expression-bodied function ever has.
  callStack.current = _body;
  try {
    return _callImpl(
      visitor,
      positionalArguments,
      namedArguments,
      typeArguments,
    );
  } catch (error) {
    callStack.recordEscape(error);
    rethrow;
  } finally {
    callStack.exit();
    D4.popActiveVisitor(previousActiveVisitor);
  }
}