src/Util/U.php
public static function array_Integer_Deserialize($input) {
        $r = array();
        preg_match_all("/([^,= ]+)=([^,= ]+)/", $input, $r);
        $result = array();
        for($i=0; $i<count($r[1]);$i++) {
            $k = $r[1][$i];
            $v = $r[2][$i];
            if ( !is_numeric($k) || !is_numeric($v) ) {
                throw new \Exception('array_Integer_Deserialize requires integers '.$k.'='.$v.' ('.$i.')');
            }
            $k = $k + 0;
            $v = $v + 0;
            if ( ! is_int($k) || ! is_int($v) ) {
                throw new \Exception('array_Integer_Deserialize requires integers '.$k.'='.$v.' ('.$i.')');
            }
            $result[$k] = $v;
        }

        return $result;
    }
public static function array_Integer_Deserialize($input) {
        $r = array();
        preg_match_all("/([^,= ]+)=([^,= ]+)/", $input, $r);
        $result = array();
        for($i=0; $i<count($r[1]);$i++) {
            $k = $r[1][$i];
            $v = $r[2][$i];
            if ( !is_numeric($k) || !is_numeric($v) ) {
                throw new \Exception('array_Integer_Deserialize requires integers '.$k.'='.$v.' ('.$i.')');
            }
            $k = $k + 0;
            $v = $v + 0;
            if ( ! is_int($k) || ! is_int($v) ) {
                throw new \Exception('array_Integer_Deserialize requires integers '.$k.'='.$v.' ('.$i.')');
            }
            $result[$k] = $v;
        }

        return $result;
    }
public static function array_Integer_Deserialize ( $ input ) { $ r = array ( ) ; preg_match_all ( "/([^,= ]+)=([^,= ]+)/" , $ input , $ r ) ; $ result = array ( ) ; for ( $ i = 0 ; $ i < count ( $ r [ 1 ] ) ; $ i ++ ) { $ k = $ r [ 1 ] [ $ i ] ; $ v = $ r [ 2 ] [ $ i ] ; if ( ! is_numeric ( $ k ) || ! is_numeric ( $ v ) ) { throw new \ Exception ( 'array_Integer_Deserialize requires integers ' . $ k . '=' . $ v . ' (' . $ i . ')' ) ; } $ k = $ k + 0 ; $ v = $ v + 0 ; if ( ! is_int ( $ k ) || ! is_int ( $ v ) ) { throw new \ Exception ( 'array_Integer_Deserialize requires integers ' . $ k . '=' . $ v . ' (' . $ i . ')' ) ; } $ result [ $ k ] = $ v ; } return $ result ; }
Deserialize an tightly serialized integer-only PHP array

$str = '1=42,2=43,3=44';
$arar = U::array_Integer_Deserialize($str);
print_r($arar); // Array ( '1' => 42 ,'2' => 43, '3' => 44 );

https://stackoverflow.com/questions/4923951/php-split-string-in-key-value-pairs
Deserialize an tightly serialized integer - only PHP array