Convert some for-in loops for performance

pkg/analyzer/lib/dart/ast/ast.dart

 // Copyright (c) 2014, 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.
 
 /**
  * Defines the AST model. The AST (Abstract Syntax Tree) model describes the
  * syntactic (as opposed to semantic) structure of Dart code. The semantic
  * structure of the code is modeled by the
  * [element model](../element/element.dart).
  *
@@ skipping 4561 matching lines @@
           return compare;
         }
       }
     }
     //
     // hides and shows
     //
     NodeList<Combinator> combinators1 = import1.combinators;
     List<String> allHides1 = new List<String>();
     List<String> allShows1 = new List<String>();
-    for (Combinator combinator in combinators1) {
+    int length1 = combinators1.length;
+    for (int i = 0; i < length1; i++) {
+      Combinator combinator = combinators1[i];
       if (combinator is HideCombinator) {
         NodeList<SimpleIdentifier> hides = combinator.hiddenNames;
-        for (SimpleIdentifier simpleIdentifier in hides) {
+        int hideLength = hides.length;
+        for (int j = 0; j < hideLength; j++) {
+          SimpleIdentifier simpleIdentifier = hides[j];
           allHides1.add(simpleIdentifier.name);
         }
       } else {
         NodeList<SimpleIdentifier> shows =
             (combinator as ShowCombinator).shownNames;
-        for (SimpleIdentifier simpleIdentifier in shows) {
+        int showLength = shows.length;
+        for (int j = 0; j < showLength; j++) {
+          SimpleIdentifier simpleIdentifier = shows[j];
           allShows1.add(simpleIdentifier.name);
         }
       }
     }
     NodeList<Combinator> combinators2 = import2.combinators;
     List<String> allHides2 = new List<String>();
     List<String> allShows2 = new List<String>();
-    for (Combinator combinator in combinators2) {
+    int length2 = combinators2.length;
+    for (int i = 0; i < length2; i++) {
+      Combinator combinator = combinators2[i];
       if (combinator is HideCombinator) {
         NodeList<SimpleIdentifier> hides = combinator.hiddenNames;
-        for (SimpleIdentifier simpleIdentifier in hides) {
+        int hideLength = hides.length;
+        for (int j = 0; j < hideLength; j++) {
+          SimpleIdentifier simpleIdentifier = hides[j];
           allHides2.add(simpleIdentifier.name);
         }
       } else {
         NodeList<SimpleIdentifier> shows =
             (combinator as ShowCombinator).shownNames;
-        for (SimpleIdentifier simpleIdentifier in shows) {
+        int showLength = shows.length;
+        for (int j = 0; j < showLength; j++) {
+          SimpleIdentifier simpleIdentifier = shows[j];
           allShows2.add(simpleIdentifier.name);
         }
       }
     }
     // test lengths of combinator lists first
     if (allHides1.length != allHides2.length) {
       return allHides1.length - allHides2.length;
     }
     if (allShows1.length != allShows2.length) {
       return allShows1.length - allShows2.length;
@@ skipping 3608 matching lines @@
   /**
    * Return the 'yield' keyword.
    */
   Token get yieldKeyword;
 
   /**
    * Return the 'yield' keyword to the given [token].
    */
   void set yieldKeyword(Token token);
 }