alias urltok {
  var %a = $1,%b = 1,%c = @:?&./#+,%d,%e,%f = 1
  while %b <= $len(%a) {
    %d = $mid(%a,%b,1)
    if %b > 1 && %d != / && %d isin %c $+ = && %d = $mid(%a,$calc(%b -1),1) return $null
    if $left(%a,7) != http:// || $mid(%a,8,1) isin %c return $null
    inc %b
  }
  goto $prop
  :attr
  %b = 1
  while %b <= $len(%a) {
    if $mid(%a,%b,1) isin ?& {
      %d = $mid(%a,%b,1)
      inc %e
      if %e = $2 {
        var %x = 1
      }
    }
    if %x {
      var %x = %x $+ $mid(%a,%b,1) 
      if $mid(%a,%b,1) = = break
    }
    inc %b
  }
  return $iif(%x,$mid(%x,3,-1),$iif($2 = 0,%e,$null))
  :dir
  %e = $count($mid(%a,8),/)
  if $2 = 0 {
    if $count(%a,http://) > 1 return 1
    return $iif($right(%a,1) = /,$calc(%e -1),%e)
  }
  %b = $calc($pos(%a,/,$calc($2 +2)) +1)
  %e = %b
  while %b <= $len(%a) {
    if $mid(%a,%b,1) isin $remove(%c,.) break
    var %x = %x $+ $mid(%a,%b,1)
    inc %b
  }
  return $iif(%e = 1,$null,%x)
  :val
  if $2 = 0 return $count(%a,=)
  %b = $pos(%a,=,$2)
  while %b <= $len(%a) {
    if $mid(%a,%b,1) isin %c break
    var %x = %x $+ $mid(%a,%b,1)
    inc %b
  }
  return $right(%x,-1)
  :protocol
  return $left(%a,4)
  :user
  %e = $mid(%a,$calc($pos(%a,://) +3))
  return $iif(. isin $left(%e,$calc($pos(%e,:) -1)),$null,$v2)
  :pass
  %e = $left(%a,$pos(%a,@,1))
  return $mid($mid(%e,$pos(%e,:,$count(%e,:))),2,-1)
  :port
  if $right($left(%a,$pos(%a,/,%f)),2) = :/ || ($v1 = //) {
    inc %f
    goto port
  }
  %e = $left(%a,$pos(%a,/,3)))
  %f = $mid(%a,$calc($pos(%e,:,$count(%e,:)) +1))
  return $iif($left(%f,$calc($pos(%f,/,1) -1)) !isnum,$null,$v1)
  :host
  if $mid(%a,8,1) !isin %c {
    %b = 8
    while %b <= $len(%a) {
      %e = $mid(%a,%b,1)
      if %e isin :/ break
      var %x = %x $+ %e
      inc %b
    }
    return $iif($left(%x,4) = www.,$right(%x,-4),%x)
  }
  if $pos(%a,@) > $pos(%a,:,%f) {
    inc %f
    goto host
  }
  return $right($mid(%a,$pos(%a,@),$pos(%a,:,$calc(%f -1))),-1)
  :anchor
  return $mid(%a,$pos(%a,$chr(35)))
}