- Consolidate String sources in the runtime libraries.

lib/string_patch.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.
 
 patch class String {
   /* patch */ factory String.fromCharCodes(Iterable<int> charCodes) {
     return _StringBase.createFromCharCodes(charCodes);
   }
 }
+
+
+/**
+ * [_StringBase] contains common methods used by concrete String
+ * implementations, e.g., _OneByteString.
+ */
+class _StringBase {
+
+  factory _StringBase._uninstantiable() {
+    throw new UnsupportedError(
+        "_StringBase can't be instaniated");
+  }
+
+  int get hashCode native "String_getHashCode";
+
+  /**
+   *  Create the most efficient string representation for specified
+   *  [codePoints].
+   */
+  static String createFromCharCodes(Iterable<int> charCodes) {
+    if (charCodes is! _ObjectArray && charCodes is! _GrowableObjectArray) {
+      charCodes = new List<int>.from(charCodes, growable: false);
+    }
+    return _createFromCodePoints(charCodes);
+  }
+
+  static String _createFromCodePoints(List<int> codePoints)
+      native "StringBase_createFromCodePoints";
+
+  String operator [](int index) native "String_charAt";
+
+  int codeUnitAt(int index) native "String_codeUnitAt";
+
+  int get length native "String_getLength";
+
+  bool get isEmpty {
+    return this.length == 0;
+  }
+
+  String operator +(String other) native "String_concat";
+
+  String concat(String other) => this + other;
+
+  String toString() {
+    return this;
+  }
+
+  bool operator ==(Object other) {
+    if (identical(this, other)) {
+      return true;
+    }
+    if ((other is !String) ||
+        (this.length != other.length)) {
+      // TODO(5413632): Compare hash codes when both are present.
+      return false;
+    }
+    return this.compareTo(other) == 0;
+  }
+
+  int compareTo(String other) {
+    int thisLength = this.length;
+    int otherLength = other.length;
+    int len = (thisLength < otherLength) ? thisLength : otherLength;
+    for (int i = 0; i < len; i++) {
+      int thisCodePoint = this.codeUnitAt(i);
+      int otherCodePoint = other.codeUnitAt(i);
+      if (thisCodePoint < otherCodePoint) {
+        return -1;
+      }
+      if (thisCodePoint > otherCodePoint) {
+        return 1;
+      }
+    }
+    if (thisLength < otherLength) return -1;
+    if (thisLength > otherLength) return 1;
+    return 0;
+  }
+
+  bool _substringMatches(int start, String other) {
+    if (other.isEmpty) return true;
+    if ((start < 0) || (start >= this.length)) {
+      return false;
+    }
+    final int len = other.length;
+    if ((start + len) > this.length) {
+      return false;
+    }
+    for (int i = 0; i < len; i++) {
+      if (this.codeUnitAt(i + start) != other.codeUnitAt(i)) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  bool endsWith(String other) {
+    return _substringMatches(this.length - other.length, other);
+  }
+
+  bool startsWith(String other) {
+    return _substringMatches(0, other);
+  }
+
+  int indexOf(String other, [int start = 0]) {
+    if (other.isEmpty) {
+      return start < this.length ? start : this.length;
+    }
+    if ((start < 0) || (start >= this.length)) {
+      return -1;
+    }
+    int len = this.length - other.length + 1;
+    for (int index = start; index < len; index++) {
+      if (_substringMatches(index, other)) {
+        return index;
+      }
+    }
+    return -1;
+  }
+
+  int lastIndexOf(String other, [int start = null]) {
+    if (start == null) start = length - 1;
+    if (other.isEmpty) {
+      return min(this.length, start);
+    }
+    if (start >= this.length) {
+      start = this.length - 1;
+    }
+    for (int index = start; index >= 0; index--) {
+      if (_substringMatches(index, other)) {
+        return index;
+      }
+    }
+    return -1;
+  }
+
+  String substring(int startIndex, [int endIndex]) {
+    if (endIndex == null) endIndex = this.length;
+
+    if ((startIndex < 0) || (startIndex > this.length)) {
+      throw new RangeError.value(startIndex);
+    }
+    if ((endIndex < 0) || (endIndex > this.length)) {
+      throw new RangeError.value(endIndex);
+    }
+    if (startIndex > endIndex) {
+      throw new RangeError.value(startIndex);
+    }
+    return _substringUnchecked(startIndex, endIndex);
+  }
+
+  String slice([int startIndex, int endIndex]) {
+    int start, end;
+    if (startIndex == null) {
+      start = 0;
+    } else if (startIndex is! int) {
+      throw new ArgumentError("startIndex is not int");
+    } else if (startIndex >= 0) {
+      start = startIndex;
+    } else {
+      start = this.length + startIndex;
+    }
+    if (start < 0 || start > this.length) {
+      throw new RangeError(
+          "startIndex out of range: $startIndex (length: $length)");
+    }
+    if (endIndex == null) {
+      end = this.length;
+    } else if (endIndex is! int) {
+      throw new ArgumentError("endIndex is not int");
+    } else if (endIndex >= 0) {
+      end = endIndex;
+    } else {
+      end = this.length + endIndex;
+    }
+    if (end < 0 || end > this.length) {
+      throw new RangeError(
+          "endIndex out of range: $endIndex (length: $length)");
+    }
+    if (end < start) {
+      throw new ArgumentError(
+          "End before start: $endIndex < $startIndex (length: $length)");
+    }
+    return _substringUnchecked(start, end);
+  }
+
+  String _substringUnchecked(int startIndex, int endIndex) {
+    assert(endIndex != null);
+    assert((startIndex >= 0) && (startIndex <= this.length));
+    assert((endIndex >= 0) && (endIndex <= this.length));
+    assert(startIndex <= endIndex);
+
+    if (startIndex == endIndex) {
+      return "";
+    }
+    if ((startIndex + 1) == endIndex) {
+      return this[startIndex];
+    }
+    return _substringUncheckedNative(startIndex, endIndex);
+  }
+
+  String _substringUncheckedNative(int startIndex, int endIndex)
+      native "StringBase_substringUnchecked";
+
+  String trim() {
+    final int len = this.length;
+    int first = 0;
+    for (; first < len; first++) {
+      if (!_isWhitespace(this.codeUnitAt(first))) {
+        break;
+      }
+    }
+    if (len == first) {
+      // String contains only whitespaces.
+      return "";
+    }
+    int last = len - 1;
+    for (; last >= first; last--) {
+      if (!_isWhitespace(this.codeUnitAt(last))) {
+        break;
+      }
+    }
+    if ((first == 0) && (last == (len - 1))) {
+      // Returns this string if it does not have leading or trailing
+      // whitespaces.
+      return this;
+    } else {
+      return _substringUnchecked(first, last + 1);
+    }
+  }
+
+  bool contains(Pattern pattern, [int startIndex = 0]) {
+    if (pattern is String) {
+      return indexOf(pattern, startIndex) >= 0;
+    }
+    return pattern.allMatches(this.substring(startIndex)).iterator.moveNext();
+  }
+
+  String replaceFirst(Pattern pattern, String replacement) {
+    if (pattern is! Pattern) {
+      throw new ArgumentError("${pattern} is not a Pattern");
+    }
+    if (replacement is! String) {
+      throw new ArgumentError("${replacement} is not a String");
+    }
+    StringBuffer buffer = new StringBuffer();
+    int startIndex = 0;
+    Iterator iterator = pattern.allMatches(this).iterator;
+    if (iterator.moveNext()) {
+      Match match = iterator.current;
+      buffer..write(this.substring(startIndex, match.start))
+            ..write(replacement);
+      startIndex = match.end;
+    }
+    return (buffer..write(this.substring(startIndex))).toString();
+  }
+
+  String replaceAll(Pattern pattern, String replacement) {
+    if (pattern is! Pattern) {
+      throw new ArgumentError("${pattern} is not a Pattern");
+    }
+    if (replacement is! String) {
+      throw new ArgumentError(
+          "${replacement} is not a String or Match->String function");
+    }
+    StringBuffer buffer = new StringBuffer();
+    int startIndex = 0;
+    for (Match match in pattern.allMatches(this)) {
+      buffer..write(this.substring(startIndex, match.start))
+            ..write(replacement);
+      startIndex = match.end;
+    }
+    return (buffer..write(this.substring(startIndex))).toString();
+  }
+
+  String replaceAllMapped(Pattern pattern, String replace(Match match)) {
+    return splitMapJoin(pattern, onMatch: replace);
+  }
+
+  static String _matchString(Match match) => match[0];
+  static String _stringIdentity(String string) => string;
+
+  String _splitMapJoinEmptyString(String onMatch(Match match),
+                                  String onNonMatch(String nonMatch)) {
+    // Pattern is the empty string.
+    StringBuffer buffer = new StringBuffer();
+    int length = this.length;
+    int i = 0;
+    buffer.write(onNonMatch(""));
+    while (i < length) {
+      buffer.write(onMatch(new _StringMatch(i, this, "")));
+      // Special case to avoid splitting a surrogate pair.
+      int code = this.codeUnitAt(i);
+      if ((code & ~0x3FF) == 0xD800 && length > i + 1) {
+        // Leading surrogate;
+        code = this.codeUnitAt(i + 1);
+        if ((code & ~0x3FF) == 0xDC00) {
+          // Matching trailing surrogate.
+          buffer.write(onNonMatch(this.substring(i, i + 2)));
+          i += 2;
+          continue;
+        }
+      }
+      buffer.write(onNonMatch(this[i]));
+      i++;
+    }
+    buffer.write(onMatch(new _StringMatch(i, this, "")));
+    buffer.write(onNonMatch(""));
+    return buffer.toString();
+  }
+
+  String splitMapJoin(Pattern pattern,
+                      {String onMatch(Match match),
+                       String onNonMatch(String nonMatch)}) {
+    if (pattern is! Pattern) {
+      throw new ArgumentError("${pattern} is not a Pattern");
+    }
+    if (onMatch == null) onMatch = _matchString;
+    if (onNonMatch == null) onNonMatch = _stringIdentity;
+    if (pattern is String) {
+      String stringPattern = pattern;
+      if (stringPattern.isEmpty) {
+        return _splitMapJoinEmptyString(onMatch, onNonMatch);
+      }
+    }
+    StringBuffer buffer = new StringBuffer();
+    int startIndex = 0;
+    for (Match match in pattern.allMatches(this)) {
+      buffer.write(onNonMatch(this.substring(startIndex, match.start)));
+      buffer.write(onMatch(match).toString());
+      startIndex = match.end;
+    }
+    buffer.write(onNonMatch(this.substring(startIndex)));
+    return buffer.toString();
+  }
+
+
+  /**
+   * Convert all objects in [values] to strings and concat them
+   * into a result string.
+   */
+  static String _interpolate(List values) {
+    int numValues = values.length;
+    var stringList = new List(numValues);
+    for (int i = 0; i < numValues; i++) {
+      stringList[i] = values[i].toString();
+    }
+    return _concatAll(stringList);
+  }
+
+  Iterable<Match> allMatches(String str) {
+    List<Match> result = new List<Match>();
+    int length = str.length;
+    int patternLength = this.length;
+    int startIndex = 0;
+    while (true) {
+      int position = str.indexOf(this, startIndex);
+      if (position == -1) {
+        break;
+      }
+      result.add(new _StringMatch(position, str, this));
+      int endIndex = position + patternLength;
+      if (endIndex == length) {
+        break;
+      } else if (position == endIndex) {
+        ++startIndex;  // empty match, advance and restart
+      } else {
+        startIndex = endIndex;
+      }
+    }
+    return result;
+  }
+
+  List<String> split(Pattern pattern) {
+    if ((pattern is String) && pattern.isEmpty) {
+      List<String> result = new List<String>(length);
+      for (int i = 0; i < length; i++) {
+        result[i] = this[i];
+      }
+      return result;
+    }
+    int length = this.length;
+    Iterator iterator = pattern.allMatches(this).iterator;
+    if (length == 0 && iterator.moveNext()) {
+      // A matched empty string input returns the empty list.
+      return <String>[];
+    }
+    List<String> result = new List<String>();
+    int startIndex = 0;
+    int previousIndex = 0;
+    while (true) {
+      if (startIndex == length || !iterator.moveNext()) {
+        result.add(this._substringUnchecked(previousIndex, length));
+        break;
+      }
+      Match match = iterator.current;
+      if (match.start == length) {
+        result.add(this._substringUnchecked(previousIndex, length));
+        break;
+      }
+      int endIndex = match.end;
+      if (startIndex == endIndex && endIndex == previousIndex) {
+        ++startIndex;  // empty match, advance and restart
+        continue;
+      }
+      result.add(this._substringUnchecked(previousIndex, match.start));
+      startIndex = previousIndex = endIndex;
+    }
+    return result;
+  }
+
+  List<int> get codeUnits => new CodeUnits(this);
+
+  Runes get runes => new Runes(this);
+
+  String toUpperCase() native "String_toUpperCase";
+
+  String toLowerCase() native "String_toLowerCase";
+
+  // Implementations of Strings methods follow below.
+  static String join(Iterable<String> strings, String separator) {
+    bool first = true;
+    List<String> stringsList = <String>[];
+    for (String string in strings) {
+      if (first) {
+        first = false;
+      } else {
+        stringsList.add(separator);
+      }
+
+      if (string is! String) {
+        throw new ArgumentError(Error.safeToString(string));
+      }
+      stringsList.add(string);
+    }
+    return concatAll(stringsList);
+  }
+
+  static String concatAll(Iterable<String> strings) {
+    _ObjectArray stringsArray;
+    if (strings is _ObjectArray) {
+      stringsArray = strings;
+      for (int i = 0; i < strings.length; i++) {
+        if (strings[i] is! String) throw new ArgumentError(strings[i]);
+      }
+    } else {
+      int len = strings.length;
+      stringsArray = new _ObjectArray(len);
+      int i = 0;
+      for (String string in strings) {
+        if (string is! String) throw new ArgumentError(string);
+        stringsArray[i++] = string;
+      }
+    }
+    return _concatAll(stringsArray);
+  }
+
+  static String _concatAll(List<String> strings)
+      native "Strings_concatAll";
+}
+
+
+class _OneByteString extends _StringBase implements String {
+  factory _OneByteString._uninstantiable() {
+    throw new UnsupportedError(
+        "_OneByteString can only be allocated by the VM");
+  }
+
+  int get hashCode native "String_getHashCode";
+
+  // Checks for one-byte whitespaces only.
+  // TODO(srdjan): Investigate if 0x85 (NEL) and 0xA0 (NBSP) are valid
+  // whitespaces for one byte strings.
+  bool _isWhitespace(int codePoint) {
+    return
+      (codePoint == 32) || // Space.
+      ((9 <= codePoint) && (codePoint <= 13)); // CR, LF, TAB, etc.
+  }
+
+  String _substringUncheckedNative(int startIndex, int endIndex)
+      native "OneByteString_substringUnchecked";
+
+  List<String> _splitWithCharCode(int charCode)
+      native "OneByteString_splitWithCharCode";
+
+  List<String> split(Pattern pattern) {
+    if ((pattern is _OneByteString) && (pattern.length == 1)) {
+      return _splitWithCharCode(pattern.codeUnitAt(0));
+    }
+    return super.split(pattern);
+  }
+}
+
+
+class _TwoByteString extends _StringBase implements String {
+  factory _TwoByteString._uninstantiable() {
+    throw new UnsupportedError(
+        "_TwoByteString can only be allocated by the VM");
+  }
+
+  // Checks for one-byte whitespaces only.
+  // TODO(srdjan): Investigate if 0x85 (NEL) and 0xA0 (NBSP) are valid
+  // whitespaces. Add checking for multi-byte whitespace codepoints.
+  bool _isWhitespace(int codePoint) {
+    return
+      (codePoint == 32) || // Space.
+      ((9 <= codePoint) && (codePoint <= 13)); // CR, LF, TAB, etc.
+  }
+}
+
+
+class _FourByteString extends _StringBase implements String {
+  factory _FourByteString._uninstantiable() {
+    throw new UnsupportedError(
+        "_FourByteString can only be allocated by the VM");
+  }
+
+  // Checks for one-byte whitespaces only.
+  // TODO(srdjan): Investigate if 0x85 (NEL) and 0xA0 (NBSP) are valid
+  // whitespaces. Add checking for multi-byte whitespace codepoints.
+  bool _isWhitespace(int codePoint) {
+    return
+      (codePoint == 32) || // Space.
+      ((9 <= codePoint) && (codePoint <= 13)); // CR, LF, TAB, etc.
+  }
+}
+
+
+class _ExternalOneByteString extends _StringBase implements String {
+  factory _ExternalOneByteString._uninstantiable() {
+    throw new UnsupportedError(
+        "_ExternalOneByteString can only be allocated by the VM");
+  }
+
+  // Checks for one-byte whitespaces only.
+  // TODO(srdjan): Investigate if 0x85 (NEL) and 0xA0 (NBSP) are valid
+  // whitespaces for one byte strings.
+  bool _isWhitespace(int codePoint) {
+    return
+      (codePoint == 32) || // Space.
+      ((9 <= codePoint) && (codePoint <= 13)); // CR, LF, TAB, etc.
+  }
+}
+
+
+class _ExternalTwoByteString extends _StringBase implements String {
+  factory _ExternalTwoByteString._uninstantiable() {
+    throw new UnsupportedError(
+        "_ExternalTwoByteString can only be allocated by the VM");
+  }
+
+  // Checks for one-byte whitespaces only.
+  // TODO(srdjan): Investigate if 0x85 (NEL) and 0xA0 (NBSP) are valid
+  // whitespaces. Add checking for multi-byte whitespace codepoints.
+  bool _isWhitespace(int codePoint) {
+    return
+      (codePoint == 32) || // Space.
+      ((9 <= codePoint) && (codePoint <= 13)); // CR, LF, TAB, etc.
+  }
+}
+
+
+class _ExternalFourByteString extends _StringBase implements String {
+  factory _ExternalFourByteString._uninstantiable() {
+    throw new UnsupportedError(
+        "ExternalFourByteString can only be allocated by the VM");
+  }
+
+  // Checks for one-byte whitespaces only.
+  // TODO(srdjan): Investigate if 0x85 (NEL) and 0xA0 (NBSP) are valid
+  // whitespaces. Add checking for multi-byte whitespace codepoints.
+  bool _isWhitespace(int codePoint) {
+    return
+      (codePoint == 32) || // Space.
+      ((9 <= codePoint) && (codePoint <= 13)); // CR, LF, TAB, etc.
+  }
+}
+
+
+class _StringMatch implements Match {
+  const _StringMatch(int this.start,
+                     String this.str,
+                     String this.pattern);
+
+  int get end => start + pattern.length;
+  String operator[](int g) => group(g);
+  int get groupCount => 0;
+
+  String group(int group) {
+    if (group != 0) {
+      throw new RangeError.value(group);
+    }
+    return pattern;
+  }
+
+  List<String> groups(List<int> groups) {
+    List<String> result = new List<String>();
+    for (int g in groups) {
+      result.add(group(g));
+    }
+    return result;
+  }
+
+  final int start;
+  final String str;
+  final String pattern;
+}