Haskellプログラミングのコツのようなもの ref: https://qiita.com/nobsun/items/ed33c22203734e706e9b

file0.txt

main = interact gonyo

file1.txt

gonyo  ::  String -> String
gonyo  =   unlines . munyo . lines

file10.txt

f  ::  Line -> Line
f  =   take 1 . drop 4

file11.txt

munyo  ::   [Line] -> [Line]
munyo  =    map (take 1 . drop 4)

file12.txt

main  ::  IO ()
main  =   interact (linesWrap onlyFifthChars)

type Line = String

onlyFifthChars  ::  [Line] -> [Line]
onlyFifthChars  =   map (take 1 . drop 4)

-- utility

linesWrap :: ([Line] -> [Line]) -> (String -> String)
linesWrap f = unlines . f . lines

file2.txt

gonyo :: String -> String
gonyo = linesWrap munyo

type Line = String

linesWrap :: ([Line] -> [Line]) -> (String -> String)
linesWrap f = unlines . f . lines

file3.txt

main :: IO ()
main = interact (linesWrap munyo)

linesWrap :: ([Line] -> [Line]) -> (String -> String)
linesWrap f = unlines . f . lines

file4.txt

p :: Line -> Bool
p = (40 >=) . length

file5.txt

munyo :: [Line] -> [Line]
munyo = filter ((40 >=) . length)

file7.txt

f :: Line -> Line
f = reverse . take 10 . reverse

file8.txt

munyo  ::   [Line] -> [Line]
munyo  =    map (reverse . take 10 . reverse)

file9.txt

main  ::  IO ()
main  =   interact (linesWrap lastTenChars)

type Line = String

lastTenChars  ::  [Line] -> [Line]
lastTenChars  =   map (reverse . take 10 . reverse)

-- utility

linesWrap :: ([Line] -> [Line]) -> (String -> String)
linesWrap f = unlines . f . lines

odai1.hs

main  ::  IO ()
main  =   interact (linesWrap shortLines)

type Line = String

shortLines  ::  [Line] -> [Line]
shortLines  =   filter ((40 >=) . length)

-- utility

linesWrap :: ([Line] -> [Line]) -> (String -> String)
linesWrap f = unlines . f . lines