| // Copyright (c) 2015, 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. |
| |
| library dart2js.constants.evaluation; |
| |
| import '../compiler.dart' show Compiler; |
| import '../universe/call_structure.dart' show CallStructure; |
| import 'expressions.dart'; |
| |
| /// Environment used for evaluating constant expressions. |
| abstract class Environment { |
| // TODO(johnniwinther): Replace this with [CoreTypes] and maybe [Backend]. |
| Compiler get compiler; |
| |
| /// Read environments string passed in using the '-Dname=value' option. |
| String readFromEnvironment(String name); |
| } |
| |
| /// The normalized arguments passed to a const constructor computed from the |
| /// actual [arguments] and the [defaultValues] of the called construrctor. |
| class NormalizedArguments { |
| final Map<dynamic /*int|String*/, ConstantExpression> defaultValues; |
| final CallStructure callStructure; |
| final List<ConstantExpression> arguments; |
| |
| NormalizedArguments(this.defaultValues, this.callStructure, this.arguments); |
| |
| /// Returns the normalized named argument [name]. |
| ConstantExpression getNamedArgument(String name) { |
| int index = callStructure.namedArguments.indexOf(name); |
| if (index == -1) { |
| // The named argument is not provided. |
| return defaultValues[name]; |
| } |
| return arguments[index + callStructure.positionalArgumentCount]; |
| } |
| |
| /// Returns the normalized [index]th positional argument. |
| ConstantExpression getPositionalArgument(int index) { |
| if (index >= callStructure.positionalArgumentCount) { |
| // The positional argument is not provided. |
| return defaultValues[index]; |
| } |
| return arguments[index]; |
| } |
| } |