Move JsString into its own file.

sdk/lib/_internal/compiler/implementation/lib/interceptors.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.
 
-#library('dart:_interceptors');
+library _interceptors;
 
-#import('dart:collection');
+import 'dart:collection';
 
-/**
- * The interceptor class for [String]. The compiler recognizes this
- * class as an interceptor, and changes references to [:this:] to
- * actually use the receiver of the method, which is generated as an extra
- * argument added to each member.
- */
-class JSString implements String {
-  const JSString();
-
-  int charCodeAt(index) {
-    if (index is !num) throw new ArgumentError(index);
-    if (index < 0) throw new RangeError.value(index);
-    if (index >= length) throw new RangeError.value(index);
-    return JS('int', r'#.charCodeAt(#)', this, index);
-  }
-
-  Iterable<Match> allMatches(String str) {
-    checkString(str);
-    return allMatchesInStringUnchecked(this, str);
-  }
-
-  String concat(String other) {
-    if (other is !String) throw new ArgumentError(other);
-    return JS('String', r'# + #', this, other);
-  }
-
-  bool endsWith(String other) {
-    checkString(other);
-    int otherLength = other.length;
-    if (otherLength > length) return false;
-    return other == substring(length - otherLength);
-  }
-
-  String replaceAll(Pattern from, String to) {
-    checkString(to);
-    return stringReplaceAllUnchecked(this, from, to);
-  }
-
-  String replaceFirst(Pattern from, String to) {
-    checkString(to);
-    return stringReplaceFirstUnchecked(this, from, to);
-  }
-
-  List<String> split(Pattern pattern) {
-    checkNull(pattern);
-    return stringSplitUnchecked(this, pattern);
-  }
-
-  List<String> splitChars() {
-    return JS('List', r'#.split("")', this);
-  }
-
-  bool startsWith(String other) {
-    checkString(other);
-    int otherLength = other.length;
-    if (otherLength > length) return false;
-    return JS('bool', r'# == #', other,
-              JS('String', r'#.substring(0, #)', this, otherLength));
-  }
-
-  String substring(int startIndex, [int endIndex]) {
-    checkNum(startIndex);
-    if (endIndex == null) endIndex = length;
-    checkNum(endIndex);
-    if (startIndex < 0 ) throw new RangeError.value(startIndex);
-    if (startIndex > endIndex) throw new RangeError.value(startIndex);
-    if (endIndex > length) throw new RangeError.value(endIndex);
-    return JS('String', r'#.substring(#, #)', this, startIndex, endIndex);
-  }
-
-  String toLowerCase() {
-    return JS('String', r'#.toLowerCase()', this);
-  }
-
-  String toUpperCase() {
-    return JS('String', r'#.toUpperCase()', this);
-  }
-
-  String trim() {
-    return JS('String', r'#.trim()', this);
-  }
-
-  List<int> get charCodes  {
-    List<int> result = new List<int>(length);
-    for (int i = 0; i < length; i++) {
-      result[i] = charCodeAt(i);
-    }
-    return result;
-  }
-}
+part 'js_string.dart';
 
 /**
  * The interceptor class for all non-primitive objects. All its
  * members are synthethized by the compiler's emitter.
  */
 class ObjectInterceptor {
   const ObjectInterceptor();
 }
 
 /**
@@ skipping 561 matching lines @@
   } else if (isJsArray(receiver)) {
     return getOrCreateCachedRuntimeType('List');
   } else {
     return UNINTERCEPTED(receiver.runtimeType);
   }
 }
 
 // TODO(lrn): These getters should be generated automatically for all
 // intercepted methods.
 get$toString(receiver) => () => toString(receiver);