php call to undefined method stdClass for lamda md

Question

I want to create a map of lambda fns to clean up strings using regexes. The keys will be group names.

I'm having an issue calling my test str on this lambda fn though.

$regex_fns = (object)[
    'LINE_DATA' => function($str) { return preg_replace('/\s*/', '', $str); }  
];

$my_key = 'LINE_DATA';
print($regex_fns->{$my_key}('    I       am     testing       removing   white space '));

There is also an example on http://sandbox.onlinephpfunctions.com/code/fd99947ff804cb056a91ffd9614a357abc7cb3bc.

Any ideas?