| // Copyright (c) 2014, 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 'core_matchers.dart'; |
| import 'interfaces.dart'; |
| |
| typedef bool _Predicate(value); |
| |
| /// A [Map] between whitespace characters and their escape sequences. |
| const _escapeMap = const { |
| '\n': r'\n', |
| '\r': r'\r', |
| '\f': r'\f', |
| '\b': r'\b', |
| '\t': r'\t', |
| '\v': r'\v', |
| '\x7F': r'\x7F', // delete |
| }; |
| |
| /// A [RegExp] that matches whitespace characters that should be escaped. |
| final _escapeRegExp = new RegExp( |
| "[\\x00-\\x07\\x0E-\\x1F${_escapeMap.keys.map(_getHexLiteral).join()}]"); |
| |
| /// Useful utility for nesting match states. |
| void addStateInfo(Map matchState, Map values) { |
| var innerState = new Map.from(matchState); |
| matchState.clear(); |
| matchState['state'] = innerState; |
| matchState.addAll(values); |
| } |
| |
| /// Takes an argument and returns an equivalent [Matcher]. |
| /// |
| /// If the argument is already a matcher this does nothing, |
| /// else if the argument is a function, it generates a predicate |
| /// function matcher, else it generates an equals matcher. |
| Matcher wrapMatcher(x) { |
| if (x is Matcher) { |
| return x; |
| } else if (x is _Predicate) { |
| return predicate(x); |
| } else { |
| return equals(x); |
| } |
| } |
| |
| /// Returns [str] with all whitespace characters represented as their escape |
| /// sequences. |
| /// |
| /// Backslash characters are escaped as `\\` |
| String escape(String str) { |
| str = str.replaceAll('\\', r'\\'); |
| return str.replaceAllMapped(_escapeRegExp, (match) { |
| var mapped = _escapeMap[match[0]]; |
| if (mapped != null) return mapped; |
| return _getHexLiteral(match[0]); |
| }); |
| } |
| |
| /// Given single-character string, return the hex-escaped equivalent. |
| String _getHexLiteral(String input) { |
| int rune = input.runes.single; |
| return r'\x' + rune.toRadixString(16).toUpperCase().padLeft(2, '0'); |
| } |