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Date: Tue, 18 Dec 2012 14:24:27 +0100
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Subject: Re: [PHP-DEV] Extension for str_replace / preg_replace with arrays
From: neufeind@php.net (Stefan Neufeind)

Hi,

On 12/18/2012 01:16 PM, Leigh wrote:
> Both str_replace and preg_replace already support some array based
> replacements, I think adding more options to these functions
> specifically would just lead to confusion.

Well, yes and no. Currently you have to supply either one string to
replace with one other or you have to supply arrays for each of them.
And this wouldn't allow to replace the second, third etc. occurence
different.

Since we already have functionality for replacing with arrays in place,
I wondered if giving it one string to replace and then an array to
choose the replacement from (rotating) would be an option. Currently
that's "unsupported" (either two strings or two arrays).

> What you're proposing can already be achieved quite easily with
> preg_replace_callback and passing your array/options into the anonymous
> function with `use`, I'd personally welcome a str_replace_callback
> counterpart.

I think you could use a callback-function but would need to add quite a
few more lines to initialise your array first, do a "next()" on the
array inside the callback-function and (how would you pass it that
array?) and still would have to handle starting from beginning of the
array again once you reach the end etc.


Kind regards,
 Stefan

> On 18 December 2012 12:08, Stefan Neufeind <neufeind@php.net
> <mailto:neufeind@php.net>> wrote:
> 
>     Hi,
> 
>     inside a framework-/scripting-project we've lately discussed
>     string-replacements with arrays.
> 
>     Currently PHP supports either replacing one string by another or
>     replacing first element from one array with first from another array.
> 
>     What I'd like to propose is for str_replace and preg_replace to
>     introduce:
>     * a functionality to replace one string with strings from an array
>     * to (optionally) allow for rolling replacements (1,2,3, 1,2,3, ...)
>     * to (optionally) allow to skip strings already replaced
>       (that means not to accidentially double-replace strings)
> 
>     This would allow to do things like
> 
>     $content = str_replace('<li>',
>       array('<li class="A">', '<li class="B">', '<li class="C">'),
>       $content);
> 
>     optionally starting over from A again. (Current default is to stop when
>     there are no more elements to replace with).
> 
> 
>     Would such a change/extension find support?
> 
> 
>     Kind regards,
>      Stefan Neufeind