Time for an 2014 update…

Task/Sorting-algorithms-Quicksort/CoffeeScript/sorting-algorithms-quicksort.coffee

@@ -1,35 +1,5 @@
-# This shows quicksort-in-place.
-quicksort = (a) ->
-  swap = (i, j) ->
-    return if i == j
-    [a[i], a[j]] = [a[j], a[i]]
-
-  divide = (v, start, end) ->
-    first_big = start
-    j = start
-    while j <= end
-      if a[j] < v
-        swap first_big, j
-        first_big += 1
-      j += 1
-    first_big
-
-  partition = (start, end) ->
-    v = a[end]
-    first_big = divide v, start, end-1
-    swap first_big, end
-    first_big
-
-  qs = (start, end) ->
-    return if start >= end
-    m = partition start, end
-    qs start, m-1
-    qs m+1, end
-
-  qs 0, a.length - 1
-
-# test
-do ->
-  a = [1, 3, 5, 7, 9, 8, 6, 4, 2, 0, 3.5]
-  quicksort(a)
-  console.log a # [ 0, 1, 2, 3, 3.5, 4, 5, 6, 7, 8, 9 ]
+quicksort = ([x, xs...]) ->
+  return [] unless x?
+  smallerOrEqual = (a for a in xs when a <= x)
+  larger = (a for a in xs when a > x)
+  (quicksort smallerOrEqual).concat(x).concat(quicksort larger)