Library prefix should be an identifier

vm/scanner.cc

 // 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.
 
 #include "vm/scanner.h"
 
 #include "vm/assert.h"
 #include "vm/flags.h"
 #include "vm/object.h"
 #include "vm/thread.h"
@@ skipping 99 matching lines @@
 bool Scanner::IsIdentStartChar(int32_t c) {
   return IsLetter(c) || (c == '_') || (c == '$');
 }
 
 
 bool Scanner::IsIdentChar(int32_t c) {
   return IsLetter(c) || IsDecimalDigit(c) || (c == '_') || (c == '$');
 }
 
 
+bool Scanner::IsIdent(const String& str) {
+  if (!str.IsOneByteString()) {

[hausner, 2011/11/21 19:53:58]

Is there a guarantee that strings will always be of the smallest type, ie. that
we could not encounter the word "if" in a two-byte string?

[siva, 2011/11/21 21:48:04]

No they are not guaranteed to be always the smallest type and hence the check to
filter those out as invalid.

On 2011/11/21 19:53:58, hausner wrote:

+    return false;
+  }
+  for (int i =  0; i < str.Length(); i++) {
+    if (!IsIdentChar(str.CharAt(i))) {

[hausner, 2011/11/21 19:53:58]

The first character in the string must be checked with IsIdentStartChar(),
otherwise "55" would pass as a valid identifier.

Also, you need to check that the string has at least one character.

[siva, 2011/11/21 21:48:04]

Good catch.

On 2011/11/21 19:53:58, hausner wrote:

+      return false;
+    }
+  }
+  return true;
+}
+
+
 void Scanner::ReadChar() {
   if (lookahead_pos_ < source_length_) {
     if (c0_ == '\n') {
       newline_seen_ = true;
       c0_pos_.line++;
       c0_pos_.column = 0;
     }
     lookahead_pos_++;
     c0_pos_.column++;
     c0_ = LookaheadChar(0);
@@ skipping 705 matching lines @@
               "%c%"PRIxPTR, kPrivateKeySeparator, key_value);
   const String& result = String::Handle(String::New(private_key));
   return result.raw();
 }
 
 
 void Scanner::InitOnce() {
 }
 
 }  // namespace dart