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Date: Wed, 8 Mar 2017 17:14:05 +0200
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To: Rowan Collins <rowan.collins@gmail.com>
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Subject: Re: [PHP-DEV] [Discussion] is_string(), string type and objects
 implementing __toString()
From: narf@devilix.net (Andrey Andreev)

Hi Rowan,

On Wed, Mar 8, 2017 at 4:29 PM, Rowan Collins <rowan.collins@gmail.com> wro=
te:
> Hi Andrey,
>
> I think this is an interesting area to explore, but do think the scope ne=
eds to be widened slightly.
>
>
> On 8 March 2017 12:25:54 GMT+00:00, Andrey Andreev <narf@devilix.net> wro=
te:
>>I ultimately wouldn't care if it's a separate function and did in fact
>>think of an is_stringable() function, but wasn't happy with the naming
>>- who's to say that e.g. integers aren't stringable? Bar
>>horribly-verbose names like
>>"string_or_objects_implementing__toString", I don't think there's a
>>way to avoid that ambiguity. :/
>>If we want a "stringable" type though
>
> Sometimes, the fact that you can't think of a good name for a function is=
 a clue that the function isn't solving a well-defined problem.
>
> In this case, why *wouldn't* the function return true for integers? If th=
e question the function is asking is "can this value be cast to string?" th=
en the answer for any integer should be "yes". If the question is "will it =
pass a strict type check as a string", then the answer for objects would al=
ways be "no". Am I missing a situation where casting an object would be saf=
e, but casting an integer wouldn't?
>

Well, it may be confusing and/or a bit inconsistent since what
__toString() does is casting (and the idea will probably be ridiculed
because of this), but putting that aside - it's not about casting at
all.
The question is rather "is this value a string?", only with the added
assumption that __toString() objects are treated as "string objects"
and thus fulfill the condition (another reason why I went for an
is_string() parameter).

It's not so much about whether casting would result in loss of data,
which is what I assume you mean by "safe", but about whether the value
was ever intended to be used as a string - an object implementing
__toString() obviously is, while the same cannot be certainly said for
integers.
An integer can be a bit flag, or a key from an id =3D> name pair, etc.

Cheers,
Andrey.