sdk files reorganization to make dart2js a proper package

sdk/lib/_internal/compiler/js_lib/regexp_helper.dart

-// 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 ? 'm' : '';
-    String i = caseSensitive ? '' : '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('',
-        '(function() {'
-         'try {'
-          'return new RegExp(#, # + # + #);'
-         '} 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<String> 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[match.length - 1] != null) return null;
-    match.length -= 1;
-    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.
-  final List<String> _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("int", "#.index", _match);
-  int get end => start + _match[0].length;
-
-  String group(int index) => _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);
-}