18 lines
360 B
Haskell
18 lines
360 B
Haskell
module MonadHelp where
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untilJust :: Monad m => m (Maybe a) -> m a
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untilJust m = go
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where
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go = do
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mayx <- m
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maybe go return mayx
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untilJustCount :: Monad m => m (Maybe a) -> m (a, Int)
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untilJustCount m = go 0
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where
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go i = do
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mayx <- m
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case mayx of
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Nothing -> go (i+1)
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Just x -> return (x,i)
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