"Reverting 14829-14832"

utils/pub/version.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.
 
 /**
  * Handles version numbers, following the [Semantic Versioning][semver] spec.
  *
  * [semver]: http://semver.org/
  */
 library version;
 
 import 'dart:math';
 
 import 'utils.dart';
 
 /** A parsed semantic version number. */
 class Version implements Comparable, VersionConstraint {
   /** No released version: i.e. "0.0.0". */
   static Version get none => new Version(0, 0, 0);
 
-  static final _PARSE_REGEX = new RegExp(
+  static const _PARSE_REGEX = const RegExp(
       r'^'                                       // Start at beginning.
       r'(\d+).(\d+).(\d+)'                       // Version number.
       r'(-([0-9A-Za-z-]+(\.[0-9A-Za-z-]+)*))?'   // Pre-release.
       r'(\+([0-9A-Za-z-]+(\.[0-9A-Za-z-]+)*))?'  // Build.
       r'$');                                     // Consume entire string.
 
   /** The major version number: "1" in "1.2.3". */
   final int major;
 
   /** The minor version number: "2" in "1.2.3". */
@@ skipping 372 matching lines @@
   static VersionConstraint parseSingleConstraint(String text) {
     if (text == 'any') {
       return new VersionRange();
     }
 
     // TODO(rnystrom): Consider other syntaxes for version constraints. This
     // one is whitespace sensitive (you can't do "< 1.2.3") and "<" is
     // unfortunately meaningful in YAML, requiring it to be quoted in a
     // pubspec.
     // See if it's a comparison operator followed by a version, like ">1.2.3".
-    var match = new RegExp(r"^([<>]=?)?(.*)$").firstMatch(text);
+    var match = const RegExp(r"^([<>]=?)?(.*)$").firstMatch(text);
     if (match != null) {
       var comparison = match[1];
       var version = new Version.parse(match[2]);
       switch (match[1]) {
         case '<=': return new VersionRange(max: version, includeMax: true);
         case '<': return new VersionRange(max: version, includeMax: false);
         case '>=': return new VersionRange(min: version, includeMin: true);
         case '>': return new VersionRange(min: version, includeMin: false);
       }
     }
 
     // Otherwise, it must be an explicit version.
     return new Version.parse(text);
   }
 }