[hs] Clean up 2020 days

hs/src/Aoc/Y2020/D01.hs

@@ -31,8 +31,9 @@ solver values = do
   let (x1, x2) = findPair values
   putStrLn $ show x1 ++ " * " ++ show x2 ++ " = " ++ show (x1 * x2)
 
-  let (y1, y2, y3) = findTriple values
+  putStrLn ""
   putStrLn ">> Part 2"
+  let (y1, y2, y3) = findTriple values
   putStrLn $ show y1 ++ " * " ++ show y2 ++ " * " ++ show y3 ++ " = " ++ show (y1 * y2 * y3)
 
 day :: Day

hs/src/Aoc/Y2020/D02.hs

@@ -37,6 +37,7 @@ solver ls = do
   putStrLn ">> Part 1"
   print $ length $ filter validCount ls
 
+  putStrLn ""
   putStrLn ">> Part 2"
   print $ length $ filter validPositions ls
 

hs/src/Aoc/Y2020/D03.hs

@@ -7,18 +7,21 @@ import           Data.List
 import           Aoc.Day
 import           Aoc.Parse
 
-parser :: Parser [[Bool]]
+type Forest = [[Bool]]
+type Slope = [Maybe Int]
+
+parser :: Parser Forest
 parser = manyLines $ many $ do
   c <- lineChar
   pure $ c == '#'
 
-slope :: Int -> Int -> [Maybe Int]
+slope :: Int -> Int -> Slope
 slope dx dy = intercalate (replicate (dy - 1) Nothing) [[Just x] | x <- [0,dx..]]
 
-onSlope :: [[Bool]] -> [Maybe Int] -> Int
+onSlope :: Forest -> Slope -> Int
-onSlope trees s = length $ filter id $ [row !! x | (row, Just x) <- zip trees s]
+onSlope trees s = length $ filter id [row !! x | (row, Just x) <- zip trees s]
 
-solver :: [[Bool]] -> IO ()
+solver :: Forest -> IO ()
 solver trees = do
   let infTrees = map cycle trees
 
@@ -26,6 +29,7 @@ solver trees = do
   let treesHit = length $ filter id $ zipWith (!!) infTrees [0,3..]
   putStrLn $ "Trees hit for slope 3-1: " ++ show treesHit
 
+  putStrLn ""
   putStrLn ">> Part 2"
   let oneOne   = onSlope infTrees $ slope 1 1
       threeOne = onSlope infTrees $ slope 3 1