Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:7131
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Date: Thu, 15 Jan 2004 20:48:33 +0100
Reply-To: Marcus Boerger <helly@php.net>
Message-ID: <132109560218.20040115204833@marcus-boerger.de>
To: Adam Maccabee Trachtenberg <adam@trachtenberg.com>
Cc: internals@lists.php.net
In-Reply-To: <Pine.LNX.4.58.0401151259140.731@miranda.org>
References: <Pine.LNX.4.58.0401151259140.731@miranda.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Subject: Re: [PHP-DEV] __toString() with strval() and settype()
From: helly@php.net (Marcus Boerger)

Hello Adam,

Thursday, January 15, 2004, 7:04:09 PM, you wrote:

> Question:

> Given an object, $obj, should strval($obj) and settype($obj, 'string')
> return $obj->__toString() if it exists?

> They currently do not, but (string) $obj does.

> Are these three operations supposed to be identical, but with
> different syntax? Or are there other differences among them?

Looking at the docs i found this:
Converting to string
You can convert a value to a string using the (string) cast, or the
strval() function. String conversion is automatically done in the scope
of an expression for you where a string is needed. This happens when
you use the echo() or print() functions, or when you compare a variable
value to a string. Reading the manual sections on Types and Type Juggling
will make the following clearer. See also settype().

That means strval($x) is equal to (string)$x.

Looking at settype() i found this:
bool settype ( mixed var, string type)
Set the type of variable var to type.
[...]
See also gettype(), type-casting and type-juggling.

That does not sound like typecasting but it dosn't sound like no
typecasting being involved too. In other words it is unclear.

Looking at TypeJuggling i found:
If you wish to force a variable to be evaluated as a certain type, see
the section on Type casting. If you wish to change the type of a variable,
see settype().


This sounds more like no typecasting but like a string representation. Which
could be result of __toString() as well as a text like 'object of type ...'
or somthing similar.

So i'd go for strval() calling __tostring() and hearing some other meanings
on settype().

-- 
Best regards,
 Marcus                            mailto:helly@php.net