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Cc: Antony Dovgal <antony@zend.com>
Date: Wed, 27 Dec 2006 12:02:29 -0800
To: php-dev Internals <internals@lists.php.net>
Subject: Return value of convert_to_*()
From: andrei@gravitonic.com (Andrei Zmievski)

Antony and I just had a spirited discussion on IRC about his latest 
patches to convert_to_unicode() and convert_to_string(). The specific 
troublesome point was conversion of IS_OBJECT type. His point was that 
since all we care about is the end result, then the function should 
return SUCCESS regardless of whether the object could convert itself to 
a string or whether we forced the conversion and got a simple "Object" 
string. I do not subscribe to this point of view. I added return values 
to conversion functions precisely because I wanted to distinguish 
between "good" and "forced" conversions. We can convert anything to 
anything, that's not a problem, but in certain cases I do care that we 
tried to convert IS_OBJECT to IS_STRING and couldn't do it without 
falling back onto the "Object" crutch. One such place is 
zend_parse_parameters(). If you say zpp(..., "s", &str, &str_len) and 
the user passes an object without __toString() method, zpp() should 
issue an error saying that it expected a string and got an object 
instead, even if we "forced" the conversion result to be a string in 
convert_to_string().

My problem with considering "Object" a "successful" conversion is this: 
why do we issue E_RECOVERABLE error if the object couldn't convert 
itself to a string? Why should the user be able to catch that and not 
my code?

Please tell me that this is a valid point of view.

-Andrei