blob: 1fc616fec2604125e1f2008cb543870120737679 [file] [log] [blame]
// Copyright (c) 2016, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
import '../boolean_selector.dart';
/// A selector that matches no inputs.
class None implements BooleanSelector {
// TODO(nweiz): Stop explicitly providing a type argument when sdk#32412 is
// fixed.
final variables = const <String>[];
const None();
bool evaluate(semantics) => false;
BooleanSelector intersection(BooleanSelector other) => this;
BooleanSelector union(BooleanSelector other) => other;
void validate(bool Function(String) isDefined) {}
String toString() => '<none>';