September 2017 Update

Task/Perfect-numbers/AppleScript/perfect-numbers-1.applescript

@@ -1,48 +1,62 @@
+-- PERFECT NUMBERS -----------------------------------------------------------
+
 -- perfect :: integer -> bool
 on perfect(n)
 
     -- isFactor :: integer -> bool
     script isFactor
-        on lambda(x)
+        on |λ|(x)
             n mod x = 0
-        end lambda
+        end |λ|
     end script
 
     -- quotient :: number -> number
     script quotient
-        on lambda(x)
+        on |λ|(x)
             n / x
-        end lambda
+        end |λ|
     end script
 
     -- sum :: number -> number -> number
     script sum
-        on lambda(a, b)
+        on |λ|(a, b)
             a + b
-        end lambda
+        end |λ|
     end script
 
     -- Integer factors of n below the square root
-    set lows to filter(isFactor, range(1, (n ^ (1 / 2)) as integer))
+    set lows to filter(isFactor, enumFromTo(1, (n ^ (1 / 2)) as integer))
 
     -- low and high factors (quotients of low factors) tested for perfection
     (n > 1) and (foldl(sum, 0, (lows & map(quotient, lows))) / 2 = n)
 end perfect
 
 
--- TEST
-
+-- TEST ----------------------------------------------------------------------
 on run
 
-    filter(perfect, range(1, 10000))
+    filter(perfect, enumFromTo(1, 10000))
 
     --> {6, 28, 496, 8128}
 
 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
 
 -- filter :: (a -> Bool) -> [a] -> [a]
 on filter(f, xs)
@@ -51,7 +65,7 @@ on filter(f, xs)
         set lng to length of xs
         repeat with i from 1 to lng
             set v to item i of xs
-            if lambda(v, i, xs) then set end of lst to v
+            if |λ|(v, i, xs) then set end of lst to v
         end repeat
         return lst
     end tell
@@ -63,7 +77,7 @@ on foldl(f, startValue, xs)
         set v to startValue
         set lng to length of xs
         repeat with i from 1 to lng
-            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
@@ -75,26 +89,12 @@ on map(f, xs)
         set lng to length of xs
         set lst to {}
         repeat with i from 1 to lng
-            set end of lst to lambda(item i of xs, i, xs)
+            set end of lst to |λ|(item i of xs, i, xs)
         end repeat
         return lst
     end tell
 end map
 
--- 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
-
 -- Lift 2nd class handler function into 1st class script wrapper
 -- mReturn :: Handler -> Script
 on mReturn(f)
@@ -102,7 +102,7 @@ on mReturn(f)
         f
     else
         script
-            property lambda : f
+            property |λ| : f
         end script
     end if
 end mReturn