September 2017 Update

Task/Knuth-shuffle/AppleScript/knuth-shuffle-3.applescript

@@ -1,12 +1,13 @@
+-- KNUTH SHUFFLE -------------------------------------------------------------
+
 -- knuthShuffle :: [a] -> [a]
-on knuthShuffle(lst)
+on knuthShuffle(xs)
 
     -- randomSwap :: [Int] -> Int -> [Int]
     script randomSwap
-        on lambda(a, i)
+        on |λ|(a, i)
             if i > 1 then
                 set iRand to random number from 1 to i
-
                 tell a
                     set tmp to item iRand
                     set item iRand to item i
@@ -16,23 +17,35 @@ on knuthShuffle(lst)
             else
                 a
             end if
-        end lambda
+        end |λ|
     end script
 
-    foldr(randomSwap, lst, range(1, length of lst))
+    foldr(randomSwap, xs, enumFromTo(1, length of xs))
 end knuthShuffle
 
 
--- TEST
-
+-- TEST ----------------------------------------------------------------------
 on run
     knuthShuffle(["alpha", "beta", "gamma", "delta", "epsilon", ¬
         "zeta", "eta", "theta", "iota", "kappa", "lambda", "mu"])
 end run
 
 
+-- GENERIC FUNCTIONS ---------------------------------------------------------
 
--- GENERIC LIBRARY FUNCTIONS
+-- enumFromTo :: Int -> Int -> [Int]
+on enumFromTo(m, n)
+    if m > n then
+        set d to -1
+    else
+        set d to 1
+    end if
+    set lst to {}
+    repeat with i from m to n by d
+        set end of lst to i
+    end repeat
+    return lst
+end enumFromTo
 
 -- foldr :: (a -> b -> a) -> a -> [b] -> a
 on foldr(f, startValue, xs)
@@ -40,7 +53,7 @@ on foldr(f, startValue, xs)
         set v to startValue
         set lng to length of xs
         repeat with i from lng to 1 by -1
-            set v to lambda(v, item i of xs, i, xs)
+            set v to |λ|(v, item i of xs, i, xs)
         end repeat
         return v
     end tell
@@ -53,21 +66,7 @@ on mReturn(f)
         f
     else
         script
-            property lambda : f
+            property |λ| : f
         end script
     end if
 end mReturn
-
--- range :: Int -> Int -> [Int]
-on range(m, n)
-    if n < m then
-        set d to -1
-    else
-        set d to 1
-    end if
-    set lst to {}
-    repeat with i from m to n by d
-        set end of lst to i
-    end repeat
-    return lst
-end range