move and change

chapter2/AverageWord.idr

@@ -0,0 +1,25 @@
+module Main
+-- import System.REPL oh god my setup is horrible
+import Data.String
+
+average : String -> Double
+average str = let numWords = wordCount str
+                  totalLength = sum (allLengths (words str)) in
+                  cast totalLength / cast numWords
+  where
+    wordCount : String -> Nat
+    wordCount str = length (words str)
+    allLengths : List String -> List Nat
+    allLengths strs = map length strs
+
+showAverage : String -> String
+showAverage str = "The average word length is: " ++ show (average str) ++ "\n"
+
+
+main : IO ()
+main = repl "Enter a string: " showAverage
+
+
+doubleSum : List Nat -> List Nat
+doubleSum xs = let sum = sum xs in
+                  [sum, sum]