| // Copyright (c) 2012, 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. |
| |
| part of _js_helper; |
| |
| // Helper method used by internal libraries. |
| regExpGetNative(JSSyntaxRegExp regexp) => regexp._nativeRegExp; |
| |
| /** |
| * Returns a native version of the RegExp with the global flag set. |
| * |
| * The RegExp's `lastIndex` property is zero when it is returned. |
| * |
| * The returned regexp is shared, and its `lastIndex` property may be |
| * modified by other uses, so the returned regexp must be used immediately |
| * when it's returned, with no user-provided code run in between. |
| */ |
| regExpGetGlobalNative(JSSyntaxRegExp regexp) { |
| var nativeRegexp = regexp._nativeGlobalVersion; |
| JS('void', '#.lastIndex = 0', nativeRegexp); |
| return nativeRegexp; |
| } |
| |
| /** |
| * Computes the number of captures in a regexp. |
| * |
| * This currently involves creating a new RegExp object with a different |
| * source and running it against the empty string (the last part is usually |
| * fast). |
| * |
| * The JSSyntaxRegExp could cache the result, and set the cache any time |
| * it finds a match. |
| */ |
| int regExpCaptureCount(JSSyntaxRegExp regexp) { |
| var nativeAnchoredRegExp = regexp._nativeAnchoredVersion; |
| var match = JS('JSExtendableArray', '#.exec("")', nativeAnchoredRegExp); |
| // The native-anchored regexp always have one capture more than the original, |
| // and always matches the empty string. |
| return match.length - 2; |
| } |
| |
| class JSSyntaxRegExp implements RegExp { |
| final String pattern; |
| final _nativeRegExp; |
| var _nativeGlobalRegExp; |
| var _nativeAnchoredRegExp; |
| |
| String toString() => 'RegExp/$pattern/'; |
| |
| JSSyntaxRegExp(String source, |
| {bool multiLine: false, bool caseSensitive: true}) |
| : this.pattern = source, |
| this._nativeRegExp = |
| makeNative(source, multiLine, caseSensitive, false); |
| |
| get _nativeGlobalVersion { |
| if (_nativeGlobalRegExp != null) return _nativeGlobalRegExp; |
| return _nativeGlobalRegExp = |
| makeNative(pattern, _isMultiLine, _isCaseSensitive, true); |
| } |
| |
| get _nativeAnchoredVersion { |
| if (_nativeAnchoredRegExp != null) return _nativeAnchoredRegExp; |
| // An "anchored version" of a regexp is created by adding "|()" to the |
| // source. This means that the regexp always matches at the first position |
| // that it tries, and you can see if the original regexp matched, or it |
| // was the added zero-width match that matched, by looking at the last |
| // capture. If it is a String, the match participated, otherwise it didn't. |
| return _nativeAnchoredRegExp = |
| makeNative('$pattern|()', _isMultiLine, _isCaseSensitive, true); |
| } |
| |
| bool get _isMultiLine => JS('bool', '#.multiline', _nativeRegExp); |
| bool get _isCaseSensitive => JS('bool', '!#.ignoreCase', _nativeRegExp); |
| |
| static makeNative( |
| String source, bool multiLine, bool caseSensitive, bool global) { |
| checkString(source); |
| String m = multiLine == true ? 'm' : ''; |
| String i = caseSensitive == true ? '' : 'i'; |
| String g = global ? 'g' : ''; |
| // We're using the JavaScript's try catch instead of the Dart one to avoid |
| // dragging in Dart runtime support just because of using RegExp. |
| var regexp = JS( |
| '', |
| r''' |
| (function(source, modifiers) { |
| try { |
| return new RegExp(source, modifiers); |
| } catch (e) { |
| return e; |
| } |
| })(#, # + # + #)''', |
| source, |
| m, |
| i, |
| g); |
| if (JS('bool', '# instanceof RegExp', regexp)) return regexp; |
| // The returned value is the JavaScript exception. Turn it into a |
| // Dart exception. |
| String errorMessage = JS('String', r'String(#)', regexp); |
| throw new FormatException('Illegal RegExp pattern ($errorMessage)', source); |
| } |
| |
| Match firstMatch(String string) { |
| List m = JS('JSExtendableArray|Null', r'#.exec(#)', _nativeRegExp, |
| checkString(string)); |
| if (m == null) return null; |
| return new _MatchImplementation(this, m); |
| } |
| |
| bool hasMatch(String string) { |
| return JS('bool', r'#.test(#)', _nativeRegExp, checkString(string)); |
| } |
| |
| String stringMatch(String string) { |
| var match = firstMatch(string); |
| if (match != null) return match.group(0); |
| return null; |
| } |
| |
| Iterable<Match> allMatches(String string, [int start = 0]) { |
| checkString(string); |
| checkInt(start); |
| if (start < 0 || start > string.length) { |
| throw new RangeError.range(start, 0, string.length); |
| } |
| return new _AllMatchesIterable(this, string, start); |
| } |
| |
| Match _execGlobal(String string, int start) { |
| Object regexp = _nativeGlobalVersion; |
| JS('void', '#.lastIndex = #', regexp, start); |
| List match = JS('JSExtendableArray|Null', '#.exec(#)', regexp, string); |
| if (match == null) return null; |
| return new _MatchImplementation(this, match); |
| } |
| |
| Match _execAnchored(String string, int start) { |
| Object regexp = _nativeAnchoredVersion; |
| JS('void', '#.lastIndex = #', regexp, start); |
| List match = JS('JSExtendableArray|Null', '#.exec(#)', regexp, string); |
| if (match == null) return null; |
| // If the last capture group participated, the original regexp did not |
| // match at the start position. |
| if (match.removeLast() != null) return null; |
| return new _MatchImplementation(this, match); |
| } |
| |
| Match matchAsPrefix(String string, [int start = 0]) { |
| if (start < 0 || start > string.length) { |
| throw new RangeError.range(start, 0, string.length); |
| } |
| return _execAnchored(string, start); |
| } |
| |
| bool get isMultiLine => _isMultiLine; |
| bool get isCaseSensitive => _isCaseSensitive; |
| } |
| |
| class _MatchImplementation implements Match { |
| final Pattern pattern; |
| // Contains a JS RegExp match object. |
| // It is an Array of String values with extra 'index' and 'input' properties. |
| // We didn't force it to be JSArray<String>, so it is JSArray<dynamic>, but |
| // containing String or `undefined` values. |
| final JSArray _match; |
| |
| _MatchImplementation(this.pattern, this._match) { |
| assert(JS('var', '#.input', _match) is String); |
| assert(JS('var', '#.index', _match) is int); |
| } |
| |
| String get input => JS('String', '#.input', _match); |
| |
| int get start => |
| JS('returns:int;depends:none;effects:none;gvn:true', '#.index', _match); |
| |
| int get end => |
| start + |
| JS('returns:int;depends:none;effects:none;gvn:true', '#[0].length', |
| _match); |
| |
| // The JS below changes the static type to avoid an implicit cast. |
| // TODO(sra): Find a nicer way to do this, e.g. unsafeCast. |
| String group(int index) => JS('String|Null', '#', _match[index]); |
| |
| String operator [](int index) => group(index); |
| |
| int get groupCount => _match.length - 1; |
| |
| List<String> groups(List<int> groups) { |
| List<String> out = []; |
| for (int i in groups) { |
| out.add(group(i)); |
| } |
| return out; |
| } |
| } |
| |
| class _AllMatchesIterable extends IterableBase<Match> { |
| final JSSyntaxRegExp _re; |
| final String _string; |
| final int _start; |
| |
| _AllMatchesIterable(this._re, this._string, this._start); |
| |
| Iterator<Match> get iterator => new _AllMatchesIterator(_re, _string, _start); |
| } |
| |
| class _AllMatchesIterator implements Iterator<Match> { |
| final JSSyntaxRegExp _regExp; |
| String _string; |
| int _nextIndex; |
| Match _current; |
| |
| _AllMatchesIterator(this._regExp, this._string, this._nextIndex); |
| |
| Match get current => _current; |
| |
| bool moveNext() { |
| if (_string == null) return false; |
| if (_nextIndex <= _string.length) { |
| var match = _regExp._execGlobal(_string, _nextIndex); |
| if (match != null) { |
| _current = match; |
| int nextIndex = match.end; |
| if (match.start == nextIndex) { |
| nextIndex++; |
| } |
| _nextIndex = nextIndex; |
| return true; |
| } |
| } |
| _current = null; |
| _string = null; // Marks iteration as ended. |
| return false; |
| } |
| } |
| |
| /** Find the first match of [regExp] in [string] at or after [start]. */ |
| Match firstMatchAfter(JSSyntaxRegExp regExp, String string, int start) { |
| return regExp._execGlobal(string, start); |
| } |