Day eight: Use Flow for more sane piping

day-08-haskell/day08-haskell.cabal

@@ -29,6 +29,7 @@ library
   build-depends:
       base >=4.7 && <5
     , containers
+    , flow
   default-language: Haskell2010
 
 executable day08-haskell-exe

day-08-haskell/package.yaml

@@ -25,6 +25,7 @@ library:
   source-dirs: src
   dependencies:
   - containers
+  - flow
 
 executables:
   day08-haskell-exe:

day-08-haskell/src/Common.hs

@@ -2,6 +2,7 @@ module Common where
 
 import Data.Foldable (toList)
 import qualified Data.Map.Strict as Map
+import Flow
       
 multiMapFromList :: Ord k => [(k, v)] -> Map.Map k [v]
 multiMapFromList = Map.fromListWith (++) . map (\(k, v) -> (k, [v]))
@@ -20,10 +21,10 @@ enumerate :: [a] -> [(Int, a)]
 enumerate = zip [0..]
 
 readWorld :: String -> World
-readWorld input = (determineSize $ lines input, readAntennas input)
+readWorld input = (lines input |> determineSize, readAntennas input)
   where
     determineSize :: [String] -> Position
-    determineSize ls = (maximum $ map length ls, length ls)
+    determineSize ls = (map length ls |> maximum, length ls)
 
 readAntennas :: String -> [Antenna]
 readAntennas input = enumerate (lines input) >>= readLine

day-08-haskell/src/Task1.hs

@@ -4,10 +4,11 @@ import Common (Position, readWorld, multiMapFromList, pairPermutations)
 import qualified Data.Map.Strict as Map
 import qualified Data.Set as Set
 import Control.Monad (join)
+import Flow
 
 task1 :: String -> Int
 task1 input = case readWorld input of
-  ((width, height), antennas) -> length $ Set.fromList $ filter isInWorld $ join $ map antinodesOfFrequency $ Map.elems $ multiMapFromList antennas
+  ((width, height), antennas) -> multiMapFromList antennas |> Map.elems |> map antinodesOfFrequency |> join |> filter isInWorld |> Set.fromList |> length
     where
       antinodesOfFrequency :: [Position] -> [Position]
       antinodesOfFrequency nodes = pairPermutations nodes >>= antinodesOfPair

day-08-haskell/src/Task2.hs

@@ -4,10 +4,11 @@ import Common (Position, readWorld, multiMapFromList, pairPermutations)
 import qualified Data.Map.Strict as Map
 import qualified Data.Set as Set
 import Control.Monad (join)
+import Flow
 
 task2 :: String -> Int
 task2 input = case readWorld input of
-  ((width, height), antennas) -> length $ Set.fromList $ join $ map antinodesOfFrequency $ Map.elems $ multiMapFromList antennas
+  ((width, height), antennas) -> multiMapFromList antennas |> Map.elems |> map antinodesOfFrequency |> join |> Set.fromList |> length
     where
       antinodesOfFrequency :: [Position] -> [Position]
       antinodesOfFrequency nodes = pairPermutations nodes >>= antinodesOfPair
@@ -19,7 +20,7 @@ task2 input = case readWorld input of
         in castInWorld a (-diffX, -diffY) ++ castInWorld b (diffX, diffY)
 
       castInWorld (sx, sy) (ox, oy) =
-        takeWhile isInWorld $ map (\f -> (sx + ox * f, sy + oy * f)) [0..]
+        map (\f -> (sx + ox * f, sy + oy * f)) [0..] |> takeWhile isInWorld
 
       isInWorld :: Position -> Bool
       isInWorld (x, y)