September 2017 Update

Task/Permutations/AppleScript/permutations-2.applescript

@@ -0,0 +1,43 @@
+to DoPermutations(aList, n)
+    --> Heaps's algorithm (Permutation by interchanging pairs) AppleScript by Jean.O.matiC
+    if n = 1 then
+        tell (a reference to Permlist) to copy aList to its end
+        -- or: copy aList as text (for concatenated results)
+    else
+        repeat with i from 1 to n
+            DoPermutations(aList, n - 1)
+            if n mod 2 = 0 then -- n is even
+                tell aList to set [item i, item n] to [item n, item i] -- swaps items i and n of aList
+            else
+                tell aList to set [item 1, item n] to [item n, item 1] -- swaps items 1 and n of aList
+            end if
+            set i to i + 1
+        end repeat
+    end if
+    return (a reference to Permlist) as list
+end DoPermutations
+
+--> Example 1 (list of words)
+set [SourceList, Permlist] to [{"Good", "Johnny", "Be"}, {}]
+DoPermutations(SourceList, SourceList's length)
+--> result (value of Permlist)
+{{"Good", "Johnny", "Be"}, {"Johnny", "Good", "Be"}, {"Be", "Good", "Johnny"}, ¬
+    {"Good", "Be", "Johnny"}, {"Johnny", "Be", "Good"}, {"Be", "Johnny", "Good"}}
+
+--> Example 2 (characters with concatenated results)
+set [SourceList, Permlist] to [{"X", "Y", "Z"}, {}]
+DoPermutations(SourceList, SourceList's length)
+--> result (value of Permlist)
+{"XYZ", "YXZ", "ZXY", "XZY", "YZX", "ZYX"}
+
+--> Example 3 (Integers)
+set [SourceList, Permlist] to [{1, 2, 3}, {}]
+DoPermutations(SourceList, SourceList's length)
+--> result (value of Permlist)
+{{1, 2, 3}, {2, 1, 3}, {3, 1, 2}, {1, 3, 2}, {2, 3, 1}, {3, 2, 1}}
+
+--> Example 4 (Integers with concatenated results)
+set [SourceList, Permlist] to [{1, 2, 3}, {}]
+DoPermutations(SourceList, SourceList's length)
+--> result (value of Permlist)
+{"123", "213", "312", "132", "231", "321"}