numberGenerator.php

<?php
/**
* $num can be 1 number, list or range
* Example
* $num = 1 => return [1]
* $num = "1,2,3,4" => return [1,2,3,4]
* $num = "1-3" => return [1,2,3]
*/
function numbersGenerator($num)
    {
        if (strpos($num, "-")) {
            list($min, $max) = explode("-", $num);
            for (; $min <= $max; $min++) {
                yield (int)$min;
            }
        }else{
            $nums = explode(",", $num);
            foreach($nums as $n){
                yield (int)$n;
            }
        }
    }