Php syntax error syntax error, unexpected '[', expecting ')' str_replace, PSR-0 Autoloader

Question

I'm dabbling w/ a 'lightweight' PSR-0 AutoLoader for a WordPress Plugin, it runs fine on my local dev server, but when i push it up to one of WPEngine's staging servers, i get this:

Parse error: syntax error, unexpected '[', expecting ')' in /nas/wp/www/staging/ahsodesigns/wp-content/plugins/AhSoFunctionality/start.php on line 30

here's the AutoLoader,

// lightweight psr-0 autoloader
spl_autoload_register(function ($classname) {
    // make sure we're only loading classes from our directory,
    if (preg_match('/AhSo/',$classname)) {
        $classname = ltrim($classname, "\\");
        preg_match('/^(.+)?([^\\\\]+)$/U', $classname, $match);
        $classname = str_replace("\\", "/", $match[1])
            . str_replace(["\\", "_"], "/", $match[2])
            . ".php";
        include_once $classname;
    }
});

the issue is on this line,

$classname = str_replace("\\", "/", $match[1])
            . str_replace(["\\", "_"], "/", $match[2])
            . ".php";

apparently it doesn't like the brackets... i've tried a few quick things, like moving the concatenation all to one line. no luck, i'm guessing it's probably some kind of php.ini thing, or maybe i've got a rogue line ending character in their that WPEngine's php config doesn't like. the file was built in phpStorm w/ Unix line separators '\n'. i wish i had more time to mess with it, but you know how that goes. thanks again stack. best. resource. ever.

Answer 1

You are using php 5.4 array notation, it's not supported in lower PHP versions. Change it to

$classname = str_replace("\\", "/", $match[1])
        . str_replace(array("\\", "_"), "/", $match[2])
        . ".php";