module Hidden.Tools (
isSymbol
, modifyFst
, modifySnd
, first
, second
, third
, modifyFirst
, modifySecond
, modifyThird
, guardEqual
, (|||)
, (&&&)
, isBit7On
, bifurcate
, cat2funcL
, skipRet
, (>..>)
) where
import Data.Char ( isAlphaNum, isSpace, isPrint, ord )
import Data.Bits ( (.&.), shiftL )
import Control.Monad ( MonadPlus, guard )
isSymbol :: Char -> Bool
isSymbol = (not . isAlphaNum) &&& (not . isSpace) &&& isPrint
modifyFst :: (a -> c) -> (a, b) -> (c, b)
modifyFst f (x, y) = (f x, y)
modifySnd :: (b -> c) -> (a, b) -> (a, c)
modifySnd f (x, y) = (x, f y)
guardEqual :: (MonadPlus m, Eq a) => m a -> m a -> m ()
guardEqual m1 m2 = do { x <- m1; y <- m2; guard (x == y) }
first :: (a, b, c) -> a
first (x, _, _) = x
second :: (a, b, c) -> b
second (_, y, _) = y
third :: (a, b, c) -> c
third (_, _, z) = z
modifyFirst :: (a -> d) -> (a, b, c) -> (d, b, c)
modifyFirst f (x, y, z) = (f x, y, z)
modifySecond :: (b -> d) -> (a, b, c) -> (a, d, c)
modifySecond f (x, y, z) = (x, f y, z)
modifyThird :: (c -> d) -> (a, b, c) -> (a, b, d)
modifyThird f (x, y, z) = (x, y, f z)
(|||),(&&&) :: (a -> Bool) -> (a -> Bool) -> a -> Bool
(p1 ||| p2) x = p1 x || p2 x
(p1 &&& p2) x = p1 x && p2 x
isBit7On :: Char -> Bool
isBit7On c = ord c .&. (shiftL 1 7) /= 0
bifurcate :: (a -> a -> b) -> a -> b
bifurcate f x = f x x
cat2funcL :: (a -> c) -> (b -> c) -> a -> b -> [c]
cat2funcL f g x y = [f x, g y ]
skipRet :: Monad m => m b -> a -> m a
skipRet p x = p >> return x
(>..>) :: Monad m => m a -> m b -> m (a, b)
m1 >..> m2 = do { x <- m1; y <- m2; return (x, y) }