Improve String and RegExp implementations.

dart/frog/leg/lib/string_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.
+
+class StringMatch implements Match {
+  const StringMatch(int this._start,
+                    String this.str,
+                    String this.pattern);
+
+  int start() => _start;
+  int end() => _start + pattern.length;
+  String operator[](int g) => group(g);
+  int groupCount() => 0;
+
+  String group(int group_) {
+    if (group_ != 0) {
+      throw new IndexOutOfRangeException(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;
+}
+
+allMatchesInStringUnchecked(receiver, str) {
+  var result = new List();
+  var length = receiver.length;
+  if (length === 0) {
+    return result;
+  }
+
+  var strLength = str.length;
+  for (var i = 0; i < strLength;) {
+    var index = str.indexOf(receiver, i);
+    if (index < 0) {
+      return result;
+    }
+    result.add(new StringMatch(index, str, receiver));
+    i = index + length;
+  }
+  return result;
+}
+
+stringContainsUnchecked(receiver, other, startIndex) {
+  if (other is String) {
+    return receiver.indexOf(other, startIndex) !== -1;
+  } else if (other is RegExp) {
+    return other.hasMatch(receiver.substring(startIndex));
+  } else {
+    var substr = receiver.substring(startIndex);
+    return other.allMatches(substr).iterator().hasNext();
+  }
+}
+
+stringReplaceAllUnchecked(receiver, from, to) {
+  if (from is String) {
+    if (from == "") {
+      if (receiver == "") {
+        return to;
+      } else {
+        StringBuffer result = new StringBuffer();
+        int length = receiver.length;
+        result.add(to);
+        for (int i = 0; i < length; i++) {
+          result.add(receiver[i]);
+          result.add(to);
+        }
+        return result.toString();
+      }
+    } else {
+      var quoter =
+        new RegExpWrapper(@'[-[\]{}()*+?.,\\^$|#\s]', false, false, true).re;

[ngeoffray, 2012/02/21 12:15:53]

Add this constant as a static final of this class?

+      var quoted = JS('String', @'$0.replace($1, "\\$&")', from, quoter);
+      var re = new RegExpWrapper(quoted, false, false, true).re;
+      return JS('String', @'$0.replace($1, $2)', receiver, re, to);
+    }
+  } else if (from is RegExp) {
+    var re = new RegExpWrapper.fromRegExp(from, true).re;
+    return JS('String', @'$0.replace($1, $2)', receiver, re, to);
+  } else {
+    // TODO(floitsch): implement generic String.replace (with patterns).
+    throw "StringImplementation.replaceAll(Pattern) UNIMPLEMENTED";
+  }
+}
+
+stringReplaceFirstUnchecked(receiver, from, to) {
+  if (from is String) {
+    return JS('String', @'$0.replace($1, $2)', receiver, from, to);
+  } else if (from is RegExp) {
+    var re = new RegExpWrapper.fromRegExp(from, false).re;
+    return JS('String', @'$0.replace($1, $2)', receiver, re, to);
+  } else {
+    // TODO(floitsch): implement generic String.replace (with patterns).
+    throw "StringImplementation.replace(Pattern) UNIMPLEMENTED";
+  }
+}
+
+stringSplitUnchecked(receiver, pattern) {
+  if (pattern is String) {
+    return JS('List', @'$0.split($1)', receiver, pattern);
+  } else if (pattern is RegExp) {
+    var re = new RegExpWrapper.fromRegExp(pattern, false).re;
+    return JS('List', @'$0.split($1)', receiver, re);
+  } else {
+    throw "StringImplementation.split(Pattern) UNIMPLEMENTED";
+  }
+}