The beauty of string parsing, parting shot

By chx ~ Posted Wed, 07/01/2009 - 07:01

Did you know that {$array} is tokenized as

<?php
  array (
    0 => 'T_CURLY_OPEN',
    1 => '{',
  ),
  array (
    0 => 'T_VARIABLE',
    1 => '$array',
  ),
  '}',
?>

however ${array} gets parsed into

<?php
  array (
    0 => 'T_DOLLAR_OPEN_CURLY_BRACES',
    1 => '${',
  ),
  array (
    0 => 'T_STRING_VARNAME',
    1 => 'array',
  ),
  '}',
?>

and then any { outside of strings is tokenized into the literal character {. In other words, there are three different tokens for the opening curly brace but there is only one token for the closing one.

Comments

the

Submitted by Pavel (not verified) on Wed, 07/01/2009 - 08:41.

the T_DOLLAR_OPEN_CURLY_BRACES isn't a token for just the opening curly brace , but for ... you know, nevermind, it's right there in the name.

that does not matter

Submitted by chx on Wed, 07/01/2009 - 23:23.

if you try to find the matching pairs of { } it wont help you that a $ is stuck to {. I am complaining about you need to check three different tokens to get all { but only one to get all } -- that's just not right.