Cat

// Quicksort in Cat
//
// This is a fairly direct translation of the standard
// recursive quicksort algorithm.

define smaller {
  [<] filter
}

define larger_or_equal {
  [>=] filter
}

define qsort {
  [
    [null]
    [uncons [dup larger_or_equal] dip [smaller] bi qsort]
    [enconcat]
  ]
  [[]]
  case
}

// Example:
[2 1 4 3 5] qsort