Add String.replaceFirstMapped.

sdk/lib/_internal/compiler/js_lib/js_string.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 _interceptors;
 
 /**
  * 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
@@ skipping 55 matching lines @@
 
   String splitMapJoin(Pattern from,
                       {String onMatch(Match match),
                        String onNonMatch(String nonMatch)}) {
     return stringReplaceAllFuncUnchecked(this, from, onMatch, onNonMatch);
   }
 
   String replaceFirst(Pattern from, String to, [int startIndex = 0]) {
     checkString(to);
     checkInt(startIndex);
-    if (startIndex < 0 || startIndex > this.length) {
-      throw new RangeError.range(startIndex, 0, this.length);
-    }
+    RangeError.checkValueInInterval(startIndex, 0, this.length, "startIndex");
     return stringReplaceFirstUnchecked(this, from, to, startIndex);
   }
 
+  String replaceFirstMapped(Pattern from, String replace(Match match),
+                            [int startIndex = 0]) {
+    checkNull(replace);
+    checkInt(startIndex);
+    RangeError.checkValueInInterval(startIndex, 0, this.length, "startIndex");
+    return stringReplaceFirstMappedUnchecked(this, from, replace, startIndex);
+  }
+
   List<String> split(Pattern pattern) {
     checkNull(pattern);
     if (pattern is String) {
       return JS('JSExtendableArray', r'#.split(#)', this, pattern);
     } else if (pattern is JSSyntaxRegExp && regExpCaptureCount(pattern) == 0) {
       var re = regExpGetNative(pattern);
       return JS('JSExtendableArray', r'#.split(#)', this, re);
     } else {
       return _defaultSplit(pattern);
     }
@@ skipping 357 matching lines @@
   Type get runtimeType => String;
 
   int get length => JS('int', r'#.length', this);
 
   String operator [](int index) {
     if (index is !int) throw new ArgumentError(index);
     if (index >= length || index < 0) throw new RangeError.value(index);
     return JS('String', '#[#]', this, index);
   }
 }