September 2017 Update

Task/Sorting-algorithms-Merge-sort/Jq/sorting-algorithms-merge-sort-1.jq

@@ -0,0 +1,22 @@
+# Input: [x,y] -- the two arrays to be merged
+# If x and y are sorted as by "sort", then the result will also be sorted:
+def merge:
+  def m:  # state: [x, y, array]  (array being the answer)
+    .[0] as $x
+    | .[1] as $y
+    | if   0 == ($x|length) then .[2] + $y
+      elif 0 == ($y|length) then .[2] + $x
+      else
+        (if $x[0] <= $y[0] then [$x[1:], $y,     .[2] + [$x[0] ]]
+         else                   [$x,     $y[1:], .[2] + [$y[0] ]]
+         end) | m
+      end;
+   [.[0], .[1], []] | m;
+
+def merge_sort:
+  if length <= 1 then .
+  else
+    (length/2 |floor) as $len
+    | . as $in
+    | [ ($in[0:$len] | merge_sort), ($in[$len:] | merge_sort) ] | merge
+  end;

Task/Sorting-algorithms-Merge-sort/Jq/sorting-algorithms-merge-sort-2.jq

@@ -0,0 +1,4 @@
+( [1, 3, 8, 9, 0, 0, 8, 7, 1, 6],
+  [170, 45, 75, 90, 2, 24, 802, 66],
+  [170, 45, 75, 90, 2, 24, -802, -66] )
+| (merge_sort == sort)