switch {
  var %r return,%n $!null,%t NOT TESTED 
  if $len($2) >= 2 %r %t
  if ($2 isnum) %r $iif($2 = 0,$iif($prop = data,%t,$len($1)),$iif($len($1) < $2,%n,$mid($1,$2,1)))
  if $1 = %n %r $iif($2 = 0,$v1,%n)
  if $2 isincs $1 { 
    if $prop = data {
      if " isin $1 %r $iif($regex(c,$1,$+(/".",$2,"(.+)")/g),$regml(c,1),$iif($regex(s,$1,$+(/,$2,"(.)")/g),$regml(s,1),%t))
      %r $iif($regex(x,$1,$2 $+ (.+)),$iif($regml(x,1) isnum,$v1,%n))
    }
    %r $iif($regex($1,/ $+ $2 $+ /g) = 1,$2,%t)
  }
  else %r %n