object.enable() anti-pattern

[Chris Angelico]

On Sun, May 12, 2013 at 5:55 AM, Robert Kern <robert.kern at gmail.com> wrote:
>> Another example of temporal coupling is json_decode in PHP: you must
>> follow it by a call to json_last_error, otherwise you have no way of
>> telling whether the json_decode function succeeded or not.
>>
>> http://php.net/manual/en/function.json-last-error.php
>
>
> I suspect that the author might say something about error checking being
> optional. But yeah, terrible API. :-)

The problem with that one isn't that error checking is optional, but
that errors are signalled with a perfectly legal return value (FALSE,
if I recall correctly - which is also returned if you json_decode a
boolean false). Better design would either throw an exception on
error, or have a unique sentinel representing the errorness of the
return value.

ChrisA