The Tokenizer class seems to do a lot of lookahead, which can potentially fall off the edge of the string. In strict error reporting mode (E_ALL) this produces a notice-level warning about an out of range string access. I see that JeLuF has been putting in isset() checks to suppress the warnings.
Since a read past end of string produces a reasonably well-defined result (ie, empty string), I wonder whether it's better just to suppress the notice with a @ on the expression. Since the bounds check happens anyway, the extra isset() doesn't _do_ anything.
As a side note: isset() on a past-end-of-string read actually itself produces a notice-level error message in PHP 4.3.2, although they seem to have turned it off by 4.3.4.
-- brion vibber (brion @ pobox.com)