isA method

@override bool isA(HTType? other)

Check wether value of this HTType can be assigned to other HTType.

Implementation

@override
bool isA(HTType? other) {
  assert(other?.isResolved ?? true);

  if (other == null) return true;

  if (other.isTop) return true;

  if (other.isBottom) return false;

  if (other is HTTypeFunction) return true;

  if (other is! HTFunctionType) return false;

  if (genericTypeParameters.length != other.genericTypeParameters.length) {
    return false;
  }
  if (other.returnType != null && !other.returnType!.isTop) {
    if (returnType != null && !returnType!.isBottom) {
      return false;
    }
  }
  for (var i = 0; i < parameterTypes.length; ++i) {
    final param = parameterTypes[i];
    HTParameterType? otherParam;
    if (other.parameterTypes.length > i) {
      otherParam = other.parameterTypes[i];
    }
    if (!param.isOptional && !param.isVariadic) {
      if (otherParam == null ||
          otherParam.isOptional != param.isOptional ||
          otherParam.isVariadic != param.isVariadic ||
          otherParam.isNamed != param.isNamed ||
          (otherParam.declType != null &&
              (param.declType == null ||
                  otherParam.declType!.isNotA(param.declType)))) {
        return false;
      }
    }
  }
  return true;
}