liftA2 is the same as liftM2

Author: mnvr

02.hs

@@ -1,9 +1,7 @@
 import Text.Parsec
-import Text.Parsec.String (Parser)
-import Control.Applicative (liftA2)
 
 main :: IO ()
-main = interact $ (++"\n") . show . liftA2 (,) p1 p2 . parseGames
+main = interact $ (++"\n") . show . ((,) <$> p1 <*> p2) . parseGames
 
 data Game = Game { gid :: Int, draw :: Draw } deriving Show
 data Draw = Draw { red :: Int, green :: Int, blue :: Int } deriving Show

03.hs

@@ -1,11 +1,11 @@
-import Control.Applicative (asum, liftA2)
+import Control.Applicative (asum)
 import Control.Monad (guard)
 import Data.Char (isDigit)
 import Data.Map qualified as M
 import Data.Maybe (catMaybes, isJust, fromJust, isNothing)
 
 main :: IO ()
-main = interact $ (++ "\n") . show . liftA2 (,) p1 p2 . parseParts
+main = interact $ (++ "\n") . show . ((,) <$> p1 <*> p2) . parseParts
 
 data Grid = Grid { rows :: [String], my :: Int, mx :: Int }
 

04.hs

@@ -1,10 +1,8 @@
 {-# LANGUAGE LambdaCase #-}
 
-import Control.Applicative (liftA2)
 import Control.Monad.State
 import Data.Map qualified as M
 import Text.Parsec hiding (State)
-import Text.Parsec.String (Parser)
 
 -- Use Parsec to parse, and the State monad to memoize
 --
@@ -13,7 +11,7 @@ import Text.Parsec.String (Parser)
 -- https://mrmr.io/memoization-in-haskell
 
 main :: IO ()
-main = interact $ (++ "\n") . show . liftA2 (,) p1 p2 . parseCards
+main = interact $ (++ "\n") . show . ((,) <$> p1 <*> p2) . parseCards
 
 data Card = Card { winning :: [Int], have :: [Int] } deriving (Show)
 

05.hs

@@ -1,10 +1,9 @@
 import Text.Parsec
 import Text.Parsec.String (Parser)
 import Control.Monad (void)
-import Control.Applicative (liftA2)
 
 main :: IO ()
-main = interact $ (++ "\n") . show . liftA2 (,) p1 p2 . parseAlmanac
+main = interact $ (++ "\n") . show . ((,) <$> p1 <*> p2) . parseAlmanac
 
 data Almanac = Almanac { seeds :: [Int], maps :: [RangesMap] } deriving Show
 type RangesMap = [RangeMap]