Unspin text in php from spun text on sentence level - php

Question

I need to neatly output spun text in a php page.
I already have the prespun text in {hi|hello|greetings} format.
I have a php code that i found elsewhere, but it does not output the spun text on sentence level, where two {{ come.
Here is the code that needs fixing.
<?php
function spinText($text){
$test = preg_match_all("#\{(.*?)\}#", $text, $out);
if (!$test) return $text;
$toFind = Array();
$toReplace = Array();
foreach($out[0] AS $id => $match){
$choices = explode("|", $out[1][$id]);
$toFind[]=$match;
$toReplace[]=trim($choices[rand(0, count($choices)-1)]);
}
return str_replace($toFind, $toReplace, $text);
}
echo spinText("{Hello|Hi|Greetings}!");;
?>
The output will be randomly chose word: Hello OR Hi OR Greetings.
However, if there is a sentence level spinning, the output is messed up.
E.g.:
{{hello|hi}.{how're|how are} you|{How's|How is} it going}
The output is
{hello.how're you|How is it going}
As you can see the text has not been spun completely.
Thank you

Answer 1

This is a recursive problem, so regular expressions aren't that great; but recursive patterns can help though:
function bla($s)
{
// first off, find the curly brace patterns (those that are properly balanced)
if (preg_match_all('#\{(((?>[^{}]+)|(?R))*)\}#', $s, $matches, PREG_OFFSET_CAPTURE)) {
// go through the string in reverse order and replace the sections
for ($i = count($matches[0]) - 1; $i >= 0; --$i) {
// we recurse into this function here
$s = substr_replace($s, bla($matches[1][$i][0]), $matches[0][$i][1], strlen($matches[0][$i][0]));
}
}
// once we're done, it should be safe to split on the pipe character
$choices = explode('|', $s);
return $choices[array_rand($choices)];
}
echo bla("{{hello|hi}.{how're|how are} you|{How's|How is} it going}"), "\n";
See also: Recursive patterns