Added Object._cid getter, optimized it. Added to (some) classes a static final _clCid. Use those to…

runtime/lib/string_patch.dart

Index: runtime/lib/string_patch.dart
===================================================================
--- runtime/lib/string_patch.dart	(revision 22603)
+++ runtime/lib/string_patch.dart	(working copy)
@@ -29,16 +29,17 @@
   static String createFromCharCodes(Iterable<int> charCodes) {
     if (charCodes != null) {
       // TODO(srdjan): Also skip copying of typed arrays.
-      if (charCodes is! _ObjectArray &&
-          charCodes is! _GrowableObjectArray &&
-          charCodes is! _ImmutableArray) {
+      final ccid = charCodes._cid;
+      if ((ccid != _ObjectArray._clCid) &&
+          (ccid != _GrowableObjectArray._clCid) &&
+          (ccid != _ImmutableArray._clCid)) {

[siva, 2013/05/13 20:38:00]

It might be more readable to have static methods in the Object class for these

Object.IsArray(charCodes);

[srdjan, 2013/05/14 17:46:31]

I am open to change it, but I think this is more readable. I would be more in
favor of the change if we need the same test on various places. TODO says that
we need to add typed array as well. IsArray should return true for typed array
as well, but createFromCharCodes does not support it yet.

         charCodes = new List<int>.from(charCodes, growable: false);
       }
 
       bool isOneByteString = true;
       for (int i = 0; i < charCodes.length; i++) {
         int e = charCodes[i];
-        if (e is! int) throw new ArgumentError(e);
+        if (e is! _Smi) throw new ArgumentError(e);
         // Is e Latin1?
         if ((e < 0) || (e > 0xFF)) {
           isOneByteString = false;
@@ -342,7 +343,7 @@
     int totalLength = 0;
     for (int i = 0; i < numValues; i++) {
       var s = values[i].toString();
-      if (isOneByteString && (s is _OneByteString)) {
+      if (isOneByteString && (s._cid == _OneByteString._clCid)) {

[siva, 2013/05/13 20:38:00]

Object.IsOneByteString(s);

[srdjan, 2013/05/14 17:46:31]

Next CL as discussed offline.

         totalLength += s.length;
       } else {
         isOneByteString = false;
@@ -448,11 +449,11 @@
     final len = strings.length;
     bool isOneByteString = true;
     int totalLength = 0;
-    if (strings is _ObjectArray) {
+    if (strings._cid == _ObjectArray._clCId) {
       stringsArray = strings;
       for (int i = 0; i < len; i++) {
         var string = strings[i];
-        if (string is _OneByteString) {
+        if (string._cid == _OneByteString._clCid) {
           totalLength += string.length;
         } else {
           isOneByteString = false;
@@ -465,7 +466,7 @@
       int i = 0;
       for (int i = 0; i < len; i++) {
         var string = strings[i];
-        if (string is _OneByteString) {
+        if (string._cid == _OneByteString.clCid) {
           totalLength += s.length;
         } else {
           isOneByteString = false;
@@ -485,7 +486,7 @@
     final stringsLength = strings.length;
     for (int i = 0; i < stringsLength; i++) {
       var e = strings[i];
-      if (e is! _OneByteString) {
+      if (e._cid != _OneByteString._clCid) {
         return _concatAllNative(strings);
       }
       totalLength += e.length;
@@ -500,6 +501,8 @@
 
 
 class _OneByteString extends _StringBase implements String {
+  static final int _clCid = "A"._cid;
+
   factory _OneByteString._uninstantiable() {
     throw new UnsupportedError(
         "_OneByteString can only be allocated by the VM");
@@ -523,7 +526,7 @@
       native "OneByteString_splitWithCharCode";
 
   List<String> split(Pattern pattern) {
-    if ((pattern is _OneByteString) && (pattern.length == 1)) {
+    if ((pattern._cid == _OneByteString._clCid) && (pattern.length == 1)) {
       return _splitWithCharCode(pattern.codeUnitAt(0));
     }
     return super.split(pattern);