To be honest, I'm not quite sure what this article is trying to point out; lambda functions (and functional-style programming) have been a part of the PHP language for a very long time -- since PHP4 to be exact. It may not be as "sexy" to look at as Lisp et al, but it's certainly been doable.<p><pre><code> $fn = create_function( "$a", "return $a * 2" );
$list = array( 1, 2, 3, 4 );
$double = array_map( $fn, $list ); // array( 2, 4, 6, 8 )
</code></pre>
or<p><pre><code> function my_filter( $a ) { return $a > 10 ? true : false; }
$list = array( 5, 10, 15, 20 );
$less = array_filter( $list, "my_filter" ); // array( 15, 20 )</code></pre>