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Date: Tue, 7 Jun 2011 12:09:50 -0300
Message-ID: <BANLkTim8pu91fkZA=hvtCu-E0H4Jxr9Bwg@mail.gmail.com>
To: John Crenshaw <johncrenshaw@priacta.com>
Cc: "internals@lists.php.net" <internals@lists.php.net>
Content-Type: multipart/alternative; boundary=90e6ba53aa1c8955b304a5209c7c
Subject: Re: [PHP-DEV] Implementation help needed: Currying RFC
From: martinscotta@gmail.com (Martin Scotta)

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Content-Type: text/plain; charset=ISO-8859-1

 Martin Scotta


On Tue, Jun 7, 2011 at 10:43 AM, John Crenshaw <johncrenshaw@priacta.com>wrote:

> >    $apos = curry strpos(..., 'a'));
> >    $apos();   // runtime error wrong param count?
> >    $apos("bar"); // fine
> >    $apos("bar", "foo"); // 'a' casted to long, used as offset?
> >    $apos("bar", "foo", 0); // run-time error wrong param count?
>
> I understand where this can be useful sometimes, but I disagree that this
> should be added as a language feature. It is still possible to implement
> this (parameter positioning in your curried function) using a function that
> returns a closure similar to the curry_left example in the RFC. One possible
> method (inspired by the C++ system for doing the same thing) would be:
>
> $apos = curry( 'strpos', _1(), 'a' ); // _1() returns a placeholder
> positioning object
>
> This isn't quite as nice as the proposed T_FILL, but on the other hand, it
> is more powerful (parameters could change order) and isn't nearly as
> confusing as the RFC syntax (which looks like perhaps strpos is being called
> in some strange way).
>
> Of course, there is also always the regular old closure, which is far more
> explicit and leaves no confusion about exactly what is being returned.
>
> No offense to anyone who loves currying, but I don't see why this should be
> implemented. There are plenty of good options available for achieving
> identical or better results without modifying the language.
>
>
Hey Jhon,

What about writing your curry idea in plain PHP, as a proof of concept.
Then you can show examples live and others can toy with it.

I'm pretty sure most php developers are not used to curry -- or at least
those who don't have functional programming skills



> John Crenshaw
> Priacta, Inc.
>

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