"Functional" php indentation

Question

I'm a big fan of 1tbs when it comes to c-like languages. Now that php got decent lambdas and closures, though, I'm not sure the style I'm using for them (fundamentally made up, has something to do with the jquery source code) is the most readable/standard option. What do you think? Somebody has some nice examples of 1tbs + lambdas and functions as parameters?

Here's a sample of my code.

function bold_search_terms($needle, $haystack) {
  return str_replace(
     $occurrencies = array_filter (
         explode(" ",$haystack),
         function ($var) use ($needle) {
            return(levenshtein($var, $needle) < 3);
         }
     ),
     array_map(
          function ($var) {
              return "<strong>$var</strong>";
          },
          $occurrencies
     ),
     $haystack
  );
}

Answer 1

I'm not a big fan of inserting lambdas in that way when they have to span multiple lines. Unfortunately PHP is quite verbose in this, needing

function($something) use ($something_else) { }

as opposed to - for example - Perl's

sub { }

where parameters and enclosed variables are assumed/detected by scope, allowing a lot more lambdas to fit in one single line.

At the end of the day it comes down to personal taste, in this case I'd break the function in parts and apply str_replace() to precalculated values.

Answer 2

If you like it a bit more concise, take some inspiration from Lisp:

function bold_search_terms($needle, $haystack) {
    return str_replace
        ($occurrences = array_filter
            (explode(" ", $haystack),
            function ($var) use ($needle)
                { return(levenshtein($var, $needle) < 3); }),
        array_map
            (function ($var)
                { return "<strong>$var</strong>"; },
            $occurrences),
        $haystack);
}

Indentation and newlines show the tree of parameters. Your solution is eminently readable as-is, though.