September Morn Update

Task/Increment-a-numerical-string/Haskell/increment-a-numerical-string-5.hs

@@ -0,0 +1,30 @@
+import Text.Read (readMaybe)
+import Data.Maybe (mapMaybe)
+
+succString :: Bool -> String -> String
+succString pruned s =
+  let succs
+        :: (Num a, Show a)
+        => a -> Maybe String
+      succs = Just . show . (1 +)
+      go w
+        | elem '.' w = (readMaybe w :: Maybe Double) >>= succs
+        | otherwise = (readMaybe w :: Maybe Integer) >>= succs
+      opt w
+        | pruned = Nothing
+        | otherwise = Just w
+  in unwords $
+     mapMaybe
+       (\w ->
+           case go w of
+             Just s -> Just s
+             _ -> opt w)
+       (words s)
+
+
+-- TEST ---------------------------------------------------
+main :: IO ()
+main =
+  (putStrLn . unlines) $
+  succString <$> [True, False] <*>
+  pure "41.0 pine martens in 1491 -1.5 mushrooms ≠ 136"