dart:html perf optimization based on runing Dromaeo benchmarks

samples/third_party/dromaeo/tests/dom-query-html.dart

 #library("dom_query_html");
 #import("dart:html");
 #import('../common/common.dart');
 #source("Common.dart");
 #source("RunnerSuite.dart");
 
 void main() {
   final int num = 40;
 
   // Try to force real results.
@@ skipping 32 matching lines @@
         ret = document.query('#testA');
         ret = document.query('#testB');
         ret = document.query('#testC');
         ret = document.query('#testD');
         ret = document.query('#testE');
         ret = document.query('#testF');
       }
     })
     .test('getElementsByTagName(div)', () {
       for (int i = 0; i < num; i++) {
-        var elems = document.queryAll('div');
-        ret = elems.last().hidden;
+        ElementList elems = document.queryAll('div');
+        for (int j = 0, len = elems.length; j < len; j++) {
+          ret = elems[j].hidden;
+        }

[vsm, 2012/03/28 18:00:14]

Please drop the loop change.  It's too far from the JS we're comparing against.

The type change (ElementList) is fine.

Ditto below.

[Jacob, 2012/03/28 21:01:31]

Done.

       }
     })
     .test('getElementsByTagName(p)', () {
       for (int i = 0; i < num; i++) {
-        final elems = document.queryAll('p');
-        ret = elems.last().hidden;
+        ElementList elems = document.queryAll('p');
+        for (int j = 0, len = elems.length; j < len; j++) {
+          ret = elems[j].hidden;
+        }
       }
     })
     .test('getElementsByTagName(a)', () {
       for (int i = 0; i < num; i++) {
-        var elems = document.queryAll('a');
-        ret = elems.last().hidden;
+        ElementList elems = document.queryAll('a');
+        for (int j = 0, len = elems.length; j < len; j++) {
+          ret = elems[j].hidden;
+        }
       }
     })
     .test('getElementsByTagName(*)', () {
       for (int i = 0; i < num; i++) {
-        var elems = document.queryAll('*');
-        ret = elems.last().hidden;
+        ElementList elems = document.queryAll('*');
+        for (int j = 0, len = elems.length; j < len; j++) {
+          ret = elems[j].hidden;
+        }
       }
     })
     .test('getElementsByTagName (not in document)', () {
       for (int i = 0; i < num; i++) {
-        var elems = document.queryAll('strong');
-        ret = elems.length == 0;
+        ElementList elems = document.queryAll('strong');
+        for (int j = 0, len = elems.length; j < len; j++) {
+          ret = elems[j].hidden;
+        }
       }
     })
     .test('getElementsByName', () {
       for (int i = 0; i < num * 20; i++) {
-        var elems = document.queryAll('[name="test$num"]');
+        ElementList elems = document.queryAll('[name="test$num"]');
         ret = elems.last().hidden;
         elems = document.queryAll('[name="test$num"]');
         ret = elems.last().hidden;
         elems = document.queryAll('[name="test$num"]');
         ret = elems.last().hidden;
         elems = document.queryAll('[name="test$num"]');
         ret = elems.last().hidden;
       }
     })
     .test('getElementsByName (not in document)', () {
       for (int i = 0; i < num * 20; i++) {
         ret = document.queryAll('[name="test"]').length == 0;
         ret = document.queryAll('[name="test"]').length == 0;
         ret = document.queryAll('[name="test"]').length == 0;
         ret = document.queryAll('[name="test"]').length == 0;
         ret = document.queryAll('[name="test"]').length == 0;
       }
     })
     .end();
 }