[PHP] 파일시스템에 접근하지 않고 realpath 와 같은 기능을 하는 함수

Because realpath() does not work on files that do not
exist, I wrote a function that does.
It replaces (consecutive) occurences of / and \\ with
whatever is in DIRECTORY_SEPARATOR, and processes /. and /.. fine.
Paths returned by get_absolute_path() contain no
(back)slash at position 0 (beginning of the string) or
position -1 (ending)
<?php
    function get_absolute_path($path) {
        $path = str_replace(array('/', '\\'), DIRECTORY_SEPARATOR, $path);
        $parts = array_filter(explode(DIRECTORY_SEPARATOR, $path), 'strlen');
        $absolutes = array();
        foreach ($parts as $part) {
            if ('.' == $part) continue;
            if ('..' == $part) {
                array_pop($absolutes);
            } else {
                $absolutes[] = $part;
            }
        }
        return implode(DIRECTORY_SEPARATOR, $absolutes);
    }
?>

A test:
<?php
    var_dump(get_absolute_path('this/is/../a/./test/.///is'));
?>
Returns: string(14) "this/a/test/is"

As you can so, it also produces Yoda-speak. :)