registerGenericConstructor static method

void registerGenericConstructor(String className, String constructorName, GenericConstructorFactory factory)

Register a generic constructor factory for a bridged class.

className - The bridged class name (e.g., 'GlobalKey'). constructorName - The constructor name ('' for default, 'named' for named). factory - Creates the native object using the provided type arguments.

Chaining: If a factory is already registered for the same key, the new factory runs first. If it returns null (unhandled type), the previously-registered factory runs as fallback. This enables downstream packages to extend type dispatches without knowledge of upstream types.

Idempotent: If the same factory (by identity) is already registered for $className.$constructorName, the call is a no-op — no extra chaining, no duplicate dispatch. Distinct factories for the same key still chain as documented above.

Implementation

static void registerGenericConstructor(
  String className,
  String constructorName,
  GenericConstructorFactory factory,
) {
  final key = '$className.$constructorName';
  final identities =
      _genericConstructorIdentities.putIfAbsent(key, () => {});
  if (!identities.add(factory)) return;
  final existing = _genericConstructors[key];
  if (existing != null) {
    // Chain: try new factory first, fall back to existing
    _genericConstructors[key] =
        (visitor, positionalArgs, namedArgs, typeArgs) {
          final result = factory(
            visitor,
            positionalArgs,
            namedArgs,
            typeArgs,
          );
          if (result != null) return result;
          return existing(visitor, positionalArgs, namedArgs, typeArgs);
        };
  } else {
    _genericConstructors[key] = factory;
  }
}