    -----------------------------------------------------------------------------
    -- |
    -- Module      :  Data.SBV.Utils.Lib
    -- Copyright   :  (c) Levent Erkok
    -- License     :  BSD3
    -- Maintainer  :  erkokl@gmail.com
    -- Stability   :  experimental
    --
    -- Misc helpers
    -----------------------------------------------------------------------------

    module Data.SBV.Utils.Lib (mlift2, mlift3, mlift4, mlift5, mlift6, mlift7, mlift8, joinArgs, splitArgs) where

    import Data.Char (isSpace)
    import Data.Maybe (fromJust, isNothing)

    -- | Monadic lift over 2-tuples
    mlift2 :: Monad m => (a' -> b' -> r) -> (a -> m a') -> (b -> m b') -> (a, b) -> m r
    mlift2 k f g (a, b) = f a >>= \a' -> g b >>= \b' -> return $ k a' b'

    -- | Monadic lift over 3-tuples
    mlift3 :: Monad m => (a' -> b' -> c' -> r) -> (a -> m a') -> (b -> m b') -> (c -> m c') -> (a, b, c) -> m r
    mlift3 k f g h (a, b, c) = f a >>= \a' -> g b >>= \b' -> h c >>= \c' -> return $ k a' b' c'

    -- | Monadic lift over 4-tuples
    mlift4 :: Monad m => (a' -> b' -> c' -> d' -> r) -> (a -> m a') -> (b -> m b') -> (c -> m c') -> (d -> m d') -> (a, b, c, d) -> m r
    mlift4 k f g h i (a, b, c, d) = f a >>= \a' -> g b >>= \b' -> h c >>= \c' -> i d >>= \d' -> return $ k a' b' c' d'

    -- | Monadic lift over 5-tuples
    mlift5 :: Monad m => (a' -> b' -> c' -> d' -> e' -> r) -> (a -> m a') -> (b -> m b') -> (c -> m c') -> (d -> m d') -> (e -> m e') -> (a, b, c, d, e) -> m r
    mlift5 k f g h i j (a, b, c, d, e) = f a >>= \a' -> g b >>= \b' -> h c >>= \c' -> i d >>= \d' -> j e >>= \e' -> return $ k a' b' c' d' e'

    -- | Monadic lift over 6-tuples
    mlift6 :: Monad m => (a' -> b' -> c' -> d' -> e' -> f' -> r) -> (a -> m a') -> (b -> m b') -> (c -> m c') -> (d -> m d') -> (e -> m e') -> (f -> m f') -> (a, b, c, d, e, f) -> m r
    mlift6 k f g h i j l (a, b, c, d, e, y) = f a >>= \a' -> g b >>= \b' -> h c >>= \c' -> i d >>= \d' -> j e >>= \e' -> l y >>= \y' -> return $ k a' b' c' d' e' y'

    -- | Monadic lift over 7-tuples
    mlift7 :: Monad m => (a' -> b' -> c' -> d' -> e' -> f' -> g' -> r) -> (a -> m a') -> (b -> m b') -> (c -> m c') -> (d -> m d') -> (e -> m e') -> (f -> m f') -> (g -> m g') -> (a, b, c, d, e, f, g) -> m r
    mlift7 k f g h i j l m (a, b, c, d, e, y, z) = f a >>= \a' -> g b >>= \b' -> h c >>= \c' -> i d >>= \d' -> j e >>= \e' -> l y >>= \y' -> m z >>= \z' -> return $ k a' b' c' d' e' y' z'

    -- | Monadic lift over 8-tuples
    mlift8 :: Monad m => (a' -> b' -> c' -> d' -> e' -> f' -> g' -> h' -> r) -> (a -> m a') -> (b -> m b') -> (c -> m c') -> (d -> m d') -> (e -> m e') -> (f -> m f') -> (g -> m g') -> (h -> m h') -> (a, b, c, d, e, f, g, h) -> m r
    mlift8 k f g h i j l m n (a, b, c, d, e, y, z, w) = f a >>= \a' -> g b >>= \b' -> h c >>= \c' -> i d >>= \d' -> j e >>= \e' -> l y >>= \y' -> m z >>= \z' -> n w >>= \w' -> return $ k a' b' c' d' e' y' z' w'

    -- Command line argument parsing code courtesy of Neil Mitchell's cmdargs package: see
    -- <https://github.com/ndmitchell/cmdargs/blob/master/System/Console/CmdArgs/Explicit/SplitJoin.hs>

    -- | Given a sequence of arguments, join them together in a manner that could be used on
    --   the command line, giving preference to the Windows @cmd@ shell quoting conventions.
    --
    --   For an alternative version, intended for actual running the result in a shell, see "System.Process.showCommandForUser"
    joinArgs :: [String] -> String
    joinArgs = unwords . map f
        where f x = q ++ g x ++ q
                where hasSpace = any isSpace x
                      q = ['\"' | hasSpace || null x]
                      g ('\\':'\"':xs)            = '\\':'\\':'\\':'\"': g xs
                      g "\\"           | hasSpace = "\\\\"
                      g ('\"':xs)                 = '\\':'\"': g xs
                      g (x':xs)                   = x' : g xs
                      g []                        = []

    data State = Init -- either I just started, or just emitted something
               | Norm -- I'm seeing characters
               | Quot -- I've seen a quote

    -- | Given a string, split into the available arguments. The inverse of 'joinArgs'.
    -- Courtesy of the cmdargs package.
    splitArgs :: String -> [String]
    splitArgs = join . f Init
        where -- Nothing is start a new string
              -- Just x is accumulate onto the existing string
              join :: [Maybe Char] -> [String]
              join [] = []
              join xs = map fromJust a : join (drop 1 b)
                where (a,b) = break isNothing xs

              f Init (x:xs) | isSpace x = f Init xs
              f Init "\"\""             = [Nothing]
              f Init "\""               = [Nothing]
              f Init xs                 = f Norm xs
              f m ('\"':'\"':'\"':xs)   = Just '\"' : f m xs
              f m ('\\':'\"':xs)        = Just '\"' : f m xs
              f m ('\\':'\\':'\"':xs)   = Just '\\' : f m ('\"':xs)
              f Norm ('\"':xs)          = f Quot xs
              f Quot ('\"':'\"':xs)     = Just '\"' : f Norm xs
              f Quot ('\"':xs)          = f Norm xs
              f Norm (x:xs) | isSpace x = Nothing : f Init xs
              f m (x:xs)                = Just x : f m xs
              f _ []                    = []