September 2017 Update

Task/Averages-Root-mean-square/AppleScript/averages-root-mean-square.applescript

@@ -0,0 +1,46 @@
+-- rootMeanSquare :: [Num] -> Real
+on rootMeanSquare(xs)
+    script
+        on |λ|(a, x)
+            a + x * x
+        end |λ|
+    end script
+
+    (foldl(result, 0, xs) / (length of xs)) ^ (1 / 2)
+end rootMeanSquare
+
+
+-- TEST -----------------------------------------------------------------------
+on run
+
+    rootMeanSquare({1, 2, 3, 4, 5, 6, 7, 8, 9, 10})
+
+    -- > 6.204836822995
+end run
+
+
+-- GENERIC FUNCTIONS ----------------------------------------------------------
+
+-- foldl :: (a -> b -> a) -> a -> [b] -> a
+on foldl(f, startValue, xs)
+    tell mReturn(f)
+        set v to startValue
+        set lng to length of xs
+        repeat with i from 1 to lng
+            set v to |λ|(v, item i of xs, i, xs)
+        end repeat
+        return v
+    end tell
+end foldl
+
+-- Lift 2nd class handler function into 1st class script wrapper
+-- mReturn :: Handler -> Script
+on mReturn(f)
+    if class of f is script then
+        f
+    else
+        script
+            property |λ| : f
+        end script
+    end if
+end mReturn