scala_traits_with_php.php

<?php

spl_autoload_register(function ($name) {
	// $exp will be the name of the class without the \with\traitname part => array_splice 
	$exp = explode("\\", $name);
	// serach from end
	$index = array_search("with", array_reverse($exp, true));
	
	if (!$index || $index - 1 == count($exp)) // also fail when value is 0
		return false;

	$beginning = $exp;
	$last = array_pop($beginning);
	$beginning = implode("\\", $beginning);

	$end = array_splice($exp, $index);
	array_shift($end); // remove the "with"
	$trait = "\\".implode("\\", $end);
	$full = ($exp[0]?"\\":"").implode("\\", $exp);

	eval(
<<<PHP
	namespace $beginning;

	class $last extends $full {
		use $trait;
	}
PHP
	);
});

test_1.php

<?php

namespace space {
	trait e {
	        public $f = "f";
	}
}

namespace {
	include 'scala_traits_with_php.php';

	class a {
		public $b = "b";
	}

	trait c {
	        public $d = "d";
	}

	$obj = new a\with\c\with\space\e;

	var_dump($obj);
}

/*

Output:

object(a\with\c\with\space\e)#2 (3) {
  ["b"]=>
  string(1) "b"
  ["d"]=>
  string(1) "d"
  ["f"]=>
  string(1) "f"
}

*/

I came up with a different version which is not recursive: https://gist.github.com/bdelespierre/7341658