supporting the final keyword for properties

Hi, The recent http://www.mail-archive.com/internals@lists.php.net/msg59301.html discussion made me wonder why did we decide not supporting the final keywords for properties as it would provide an easy way for read-only attributes (const would be a better choice in performance wise, but then you can only set it in your declaration where no dynamic expression is allowed.) I would like it to work the same way as it does in java( http://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.12.4) eg. you can set the initial value either in the declaration or later on, but after it is set, you can't change it, trying to do that would create a recoverable fatal error (or throwing an exception which extends RuntimeException). What do you think? Would this be viable? Is there any still-present reason why we shouldn't support that? -- Ferenc Kovács @Tyr43l - http://tyrael.hu