Small cleanups in RegExp to avoid generating lots of code just because there is a try/catch in our …

sdk/lib/core/regexp.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 dart.core;
 
 /**
  * [Match] contains methods to manipulate a regular expression match.
  *
  * Iterables of [Match] objects are returned from [RegExp] matching methods.
@@ skipping 76 matching lines @@
  * a string.
  *
  *     RegExp exp = new RegExp(r"(\w+)");
  *     String str = "Parse my string";
  *     Iterable<Match> matches = exp.allMatches(str);
  */
 abstract class RegExp implements Pattern {
   /**
    * Constructs a regular expression. The default implementation of a
    * [RegExp] sets [multiLine] to false and [caseSensitive] to true.
+   * Throws a [FormatException] if [pattern] is not a valid regular
+   * exression pattern.
    */
   external factory RegExp(String pattern, {bool multiLine: false,
                                            bool caseSensitive: true});
 
   /**
    * Searches for the first match of the regular expression
    * in the string [str]. Returns `null` if there is no match.
    */
   Match firstMatch(String str);
 
@@ skipping 22 matching lines @@
   /**
    * Whether this regular expression matches multiple lines.
    */
   bool get isMultiLine;
 
   /**
    * Whether this regular expression is case insensitive.
    */
   bool get isCaseSensitive;
 }