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Date: Wed, 19 Dec 2012 17:18:36 -0600
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Subject: Re: [PHP-DEV] Extension for str_replace / preg_replace with arrays
From: larry@garfieldtech.com (Larry Garfield)

On 12/18/12 7:44 AM, Leigh wrote:
> On 18 December 2012 13:24, Stefan Neufeind <neufeind@php.net> wrote:
>
>> 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).
>>
>
> It's certainly possible to implement, but personally it feels like odd
> behaviour. I don't know what other people think about it.
>
>
>> 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.
>>
>
> You pass the array using "use". You could do it something like this:
>
> $replacements = array(
>      'one', 'two', 'three'
> );
>
> $result = preg_replace_callback(
>      '/word/',
>      function($matches) use (&$replacements) {
>          $current = current($replacements);
>          next($replacements) || reset($replacements);
>          return $current;
>      },
>      'word word word word word'
> );
>
> var_dump($result);
>
> Output:
>
> string(21) "one two three one two"

You could likely simplify the code even further using an infinite iterator:

http://us1.php.net/infiniteiterator

$result = preg_replace_callback(
     '/word/',
     function($matches) use (&$replacements_iterator) {
         return $replacements->next();
     },
     'word word word word word'
);

--Larry Garfield