Use == instead of identical for integers.

lib/compiler/implementation/string_validator.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.
 
 // Check the validity of string literals.
 
 library stringvalidator;
 
 import "dart2jslib.dart";
 import "tree/tree.dart";
@@ skipping 35 matching lines @@
 
   static StringQuoting quotingFromString(SourceString sourceString) {
     Iterator<int> source = sourceString.iterator();
     bool raw = false;
     int quoteLength = 1;
     int quoteChar = source.next();
     if (quoteChar === $r) {
       raw = true;
       quoteChar = source.next();
     }
-    assert(identical(quoteChar, $SQ) || identical(quoteChar, $DQ));
+    assert(quoteChar == $SQ || quoteChar == $DQ);
     // String has at least one quote. Check it if has three.
     // If it only have two, the string must be an empty string literal,
     // and end after the second quote.
     bool multiline = false;
-    if (source.hasNext() && identical(source.next(), quoteChar) && source.hasNext()) {
+    if (source.hasNext() && source.next() == quoteChar && source.hasNext()) {
       int code = source.next();
-      assert(identical(code, quoteChar));  // If not, there is a bug in the parser.
+      assert(code == quoteChar);  // If not, there is a bug in the parser.
       quoteLength = 3;
       // Check if a multiline string starts with a newline (CR, LF or CR+LF).
       if (source.hasNext()) {
         code = source.next();
-        if (identical(code, $CR)) {
+        if (code == $CR) {
           quoteLength += 1;
-          if (source.hasNext() && identical(source.next(), $LF)) {
+          if (source.hasNext() && source.next() == $LF) {
             quoteLength += 1;
           }
-        } else if (identical(code, $LF)) {
+        } else if (code == $LF) {
           quoteLength += 1;
         }
       }
     }
     return StringQuoting.getQuoting(quoteChar, raw, quoteLength);
   }
 
   void stringParseError(String message, Token token, int offset) {
     listener.cancel("$message @ $offset", token : token);
   }
 
   /**
    * Validates the escape sequences and special characters of a string literal.
    * Returns a DartString if valid, and null if not.
    */
   DartString validateString(Token token,
                             int startOffset,
                             SourceString string,
                             StringQuoting quoting) {
     // We only need to check for invalid x and u escapes, for line
     // terminators in non-multiline strings, and for invalid Unicode
     // scalar values (either directly or as u-escape values).
     int length = 0;
     int index = startOffset;
     bool containsEscape = false;
     for(Iterator<int> iter = string.iterator(); iter.hasNext(); length++) {
       index++;
       int code = iter.next();
-      if (identical(code, $BACKSLASH)) {
+      if (code == $BACKSLASH) {
         if (quoting.raw) continue;
         containsEscape = true;
         if (!iter.hasNext()) {
           stringParseError("Incomplete escape sequence",token, index);
           return null;
         }
         index++;
         code = iter.next();
-        if (identical(code, $x)) {
+        if (code == $x) {
           for (int i = 0; i < 2; i++) {
             if (!iter.hasNext()) {
               stringParseError("Incomplete escape sequence", token, index);
               return null;
             }
             index++;
             code = iter.next();
             if (!isHexDigit(code)) {
               stringParseError("Invalid character in escape sequence",
                                token, index);
               return null;
             }
           }
           // A two-byte hex escape can't generate an invalid value.
           continue;
-        } else if (identical(code, $u)) {
+        } else if (code == $u) {
           int escapeStart = index - 1;
           index++;
           code = iter.next();
           int value = 0;
           if (code == $OPEN_CURLY_BRACKET) {
             // expect 1-6 hex digits.
             int count = 0;
             index++;
             code = iter.next();
             do {
@@ skipping 40 matching lines @@
       }
     }
     // String literal successfully validated.
     if (quoting.raw || !containsEscape) {
       // A string without escapes could just as well have been raw.
       return new DartString.rawString(string, length);
     }
     return new DartString.escapedString(string, length);
   }
 }