index.php

<?php

$rule   = "foo(foo,'bar') = in_array(1, ('1', '2'))";

$ruler = new Hoa\Ruler\Ruler();
$ruler->addFunction('foo', function(array $args) {
    return $args[0] == $args[1];
});
$ruler->addFunction('in_array', function(array $args) {
    return 1;
    return in_array($args[0], $args[1]);
});
$object = $ruler->interprete($rule);

$context = new Hoa\Ruler\Asserter\Context();
$context['foo'] = 'bar';

print "<pre>";
var_dump($ruler->assert($rule, $context));
print "</pre>";