diff options
Diffstat (limited to 'Utility/Monad.hs')
| -rw-r--r-- | Utility/Monad.hs | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/Utility/Monad.hs b/Utility/Monad.hs index abe06f3..6cd2c5e 100644 --- a/Utility/Monad.hs +++ b/Utility/Monad.hs @@ -12,6 +12,7 @@ module Utility.Monad ( getM, anyM, allM, + partitionM, untilTrue, ifM, (<||>), @@ -45,6 +46,13 @@ allM :: Monad m => (a -> m Bool) -> [a] -> m Bool allM _ [] = return True allM p (x:xs) = p x <&&> allM p xs +partitionM :: Monad m => (a -> m Bool) -> [a] -> m ([a], [a]) +partitionM _ [] = return ([], []) +partitionM p (x:xs) = do + r <- p x + (as, bs) <- partitionM p xs + return $ if r then (x:as, bs) else (as, x:bs) + {- Runs an action on values from a list until it succeeds. -} untilTrue :: Monad m => [a] -> (a -> m Bool) -> m Bool untilTrue = flip anyM |