vlastachu on Use Haskell for shell scripting

Comment on Use Haskell for shell scripting parent

I'm not good enough haskell programmer, but there is possible solution (records as you mentioned).

    import Prelude hiding ((-))

    data Grep = Grep {isRecursive :: Bool, maxCount :: Maybe Int} --etc
        deriving (Show)
    grep = Grep False Nothing
    --short pseudonim
    r :: Grep -> Grep
    r command = command{isRecursive = True}
    m :: Int -> Grep -> Grep
    m num command = command{maxCount = Just num}
    
    (-) :: a -> (a -> a) -> a
    (-) command flag = flag command
    ourGrep = grep -m 50 -r 
    
    main = print ourGrep -- > Grep {isRecursive = True, maxCount = Just 50}
    
    --then we should write monad which execute that data

mercurial 11y

Yes, that's exactly what I wouldn't want to type. Also, your record is going to blow up in the likely case another utility uses a recursive flag, because of Haskell's pervasive namespacing problems.

tel 11y

It probably wouldn't be too hard to do something like

    grep "foo"
      & "recursive" <~ True
      & "maxCount"  <~ 100

in a typesafe way. It just probably wouldn't be worth the complexity. It also probably couldn't be a straight `IO` action then, which was a design constraint of Gabriel's.

Comments