23 lines
591 B
Haskell
23 lines
591 B
Haskell
module Utils where
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import Control.Monad.IO.Class
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import Data.List.Extra (stripSuffix)
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import Data.Maybe (isJust)
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-- | A shortcut for `liftIO`.
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io :: MonadIO m => IO a -> m a
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io = liftIO
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-- | A helper for throwing an error if something is `Nothing`
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just :: String -> Maybe a -> a
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just _ (Just val) = val
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just err Nothing = error ("Missing: " ++ err)
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-- | Test for whether something listy has a suffix
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hasSuffix :: Eq a => [a] -> [a] -> Bool
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hasSuffix s = isJust . stripSuffix s
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-- | The same second as from arrows et al.
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second :: (a -> b) -> (c, a) -> (c, b)
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second f (a, b) = (a, f b)
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