How do I rewrite this compress() function to not use a while() loop?

Question

I have the following compress() function:

function compress($input){
   $from = array("\r\n", "\n");
   $to = array('', '');
   $output = str_replace($from, $to, $input);
   while(true){
      $output = str_replace("  ", " ", $output);
      if (strpos($output, "  ") === FALSE){
         break;
      }
   }
   return $output;
}

I'm using it to compress the output HTML code to not contain any linebreaks, nor more than 2 subsequent spaces.

I was wondering whether this would be faster and more optimized if done using regex replace. However, even if it would, I'm not sure how to do it.

Any ideas?

Answer 1

How about:

return preg_replace(
    '# {2,}#',
    '  ',
    preg_replace(
        '#\r?\n#s',
        '',
        $input
    )
);

I believe that will do what you're suggesting, and no more. As for whether it's faster or more efficient, you'd have to run some tests, I can't say offhand. preg_replace is generally relatively expensive. I'm calling it twice here, so there's a fair amount of overhead. But it's an example of how you might do it with p_r.