Relevanssi part number checker

relevanssi-pn.php

function rlv_is_a_pn($candidate) {
	$array = str_split($candidate);
	$has_letters = false;
	$has_numbers = false;
	foreach ($array as $letter) {
		if (is_numeric($letter)) {
			$has_numbers = true;
		}
		else {
			$has_letters = true;
		}
		if ($has_numbers && $has_letters) return true;
	}
	return $false;
}

add_filter('relevanssi_remove_punctuation', 'cut_search_to_6', 11);
function cut_search_to_6($a) {
	if (rlv_is_a_pn($a)) {
	    $a = substr($a, 0, 6);
	}
	return $a;
}