addressing 3 previous review comments

frog/tokenizer.dart

 // Copyright (c) 2011, 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.
 // Generated by scripts/tokenizer_gen.py.
 
 
 interface TokenSource {
   Token next();
 }
 
@@ skipping 248 matching lines @@
   Token _makeStringToken(List<int> buf, bool isPart) {
     final s = new String.fromCharCodes(buf);
     final kind = isPart ? TokenKind.STRING_PART : TokenKind.STRING;
     return new LiteralToken(kind, _source, _startIndex, _index, s);
   }
 
   Token _makeRawStringToken(bool isMultiline) {
     String s;
     if (isMultiline) {
       // Skip initial newline in multiline strings
-      if (_source.text[_startIndex + 4] == '\n') {
-        s = _source.text.substring(_startIndex + 5, _index - 3);
-      } else {
-        s = _source.text.substring(_startIndex + 4, _index - 3);
-      }
+      int start = _startIndex + 4;
+      if (_source.text[start] == '\n') start++;
+      s = _source.text.substring(start, _index - 3);
     } else {
       s = _source.text.substring(_startIndex + 2, _index - 1);
     }
     return new LiteralToken(TokenKind.STRING, _source, _startIndex, _index, s);
   }
 
   Token finishMultilineString(int quote) {
-    var buf = new List<int>();
+    var buf = <int>[];
     while (true) {
       int ch = _nextChar();
       if (ch == 0) {
         return _errorToken();
       } else if (ch == quote) {
         if (_maybeEatChar(quote)) {
           if (_maybeEatChar(quote)) {
             return _makeStringToken(buf, false);
           }
           buf.add(quote);
@@ skipping 47 matching lines @@
       }
     }
     return finishStringBody(quote);
   }
 
   Token finishRawString(int quote) {
     if (_maybeEatChar(quote)) {
       if (_maybeEatChar(quote)) {
         return finishMultilineRawString(quote);
       } else {
-        return _makeStringToken(new List<int>(), false);
+        return _makeStringToken(<int>[], false);
       }
     }
     while (true) {
       int ch = _nextChar();
       if (ch == quote) {
         return _makeRawStringToken(false);
       } else if (ch == 0) {
         return _errorToken();
       }
     }
@@ skipping 115 matching lines @@
       }
     }
     int kind = getIdentifierKind();
     if (kind == TokenKind.IDENTIFIER) {
       return _finishToken(TokenKind.IDENTIFIER);
     } else {
       return _finishToken(kind);
     }
   }
 }