FunctionArg.fromJson constructor

FunctionArg.fromJson(Object? json_)

Returns a new instance from a JSON value. May throw if the value does not have the expected structure.

Implementation

factory FunctionArg.fromJson(Object? json_) {
  Object? json = json_;
  if (json is Map) {
    final MapEntry(:key, :value) =
        json.entries.firstWhere((e) => e.key != 'runtimeType');
    json = (
      key is int ? key : _spec.cases.indexWhere((c) => c.label == key),
      value,
    );
  }
  return switch (json) {
    (0, final value) ||
    [0, final value] =>
      FunctionArgNamed(FunctionArgExprNamed.fromJson(value)),
    (1, final value) ||
    [1, final value] =>
      FunctionArgUnnamed(FunctionArgExpr.fromJson(value)),
    _ => throw Exception('Invalid JSON $json_'),
  };
}