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lens Control.Lens.Traversal This generalizes mapAccumR to an arbitrary Traversal.
mapAccumR ≡ mapAccumROf traverse
mapAccumROf accumulates State from right to left.mapAccumROf :: Iso s t a b -> (acc -> a -> (acc, b)) -> acc -> s -> (acc, t) mapAccumROf :: Lens s t a b -> (acc -> a -> (acc, b)) -> acc -> s -> (acc, t) mapAccumROf :: Traversal s t a b -> (acc -> a -> (acc, b)) -> acc -> s -> (acc, t)
mapAccumROf :: LensLike (Backwards (State acc)) s t a b -> (acc -> a -> (acc, b)) -> acc -> s -> (acc, t)
mapMOf :: LensLike (WrappedMonad m) s t a b -> (a -> m b) -> s -> m tlens Control.Lens.Traversal Map each element of a structure targeted by a Lens to a monadic action, evaluate these actions from left to right, and collect the results.
>>> mapMOf both (\x -> [x, x + 1]) (1,3) [(1,3),(1,4),(2,3),(2,4)]
mapM ≡ mapMOf traverse imapMOf l ≡ forM l . Indexed
mapMOf :: Monad m => Iso s t a b -> (a -> m b) -> s -> m t mapMOf :: Monad m => Lens s t a b -> (a -> m b) -> s -> m t mapMOf :: Monad m => Traversal s t a b -> (a -> m b) -> s -> m t
mapConcurrently :: Traversable t => (a -> IO b) -> t a -> IO (t b)async Control.Concurrent.Async Maps an IO-performing function over any Traversable data type, performing all the IO actions concurrently, and returning the original data structure with the arguments replaced by the results. If any of the actions throw an exception, then all other actions are cancelled and the exception is re-thrown. For example, mapConcurrently works with lists:
pages <- mapConcurrently getURL ["url1", "url2", "url3"]
If you just have a list of actions, run them concurrently withresults <- mapConcurrently id [act1, act2, act3]
NOTE: mapConcurrently will immediately spawn a thread for each element of the Traversable, so running this on large inputs can lead to resource exhaustion (of memory, file descriptors, or other limited resources). To avoid unbounded resource usage, see Control.Concurrent.Stream.mapConcurrently_ :: Foldable f => (a -> IO b) -> f a -> IO ()async Control.Concurrent.Async mapConcurrently_ is mapConcurrently with the return value discarded; a concurrent equivalent of mapM_.
mapConcurrently :: Traversable t => (a -> IO b) -> t a -> IO (t b)async Control.Concurrent.Async.Internal Maps an IO-performing function over any Traversable data type, performing all the IO actions concurrently, and returning the original data structure with the arguments replaced by the results. If any of the actions throw an exception, then all other actions are cancelled and the exception is re-thrown. For example, mapConcurrently works with lists:
pages <- mapConcurrently getURL ["url1", "url2", "url3"]
If you just have a list of actions, run them concurrently withresults <- mapConcurrently id [act1, act2, act3]
NOTE: mapConcurrently will immediately spawn a thread for each element of the Traversable, so running this on large inputs can lead to resource exhaustion (of memory, file descriptors, or other limited resources). To avoid unbounded resource usage, see Control.Concurrent.Stream.mapConcurrently_ :: Foldable f => (a -> IO b) -> f a -> IO ()async Control.Concurrent.Async.Internal mapConcurrently_ is mapConcurrently with the return value discarded; a concurrent equivalent of mapM_.
mapConcurrentlyBounded :: Int -> (a -> IO b) -> [a] -> IO [b]async Control.Concurrent.Stream Concurrent map over a list of values, using a bounded number of threads.
mapAccumLM :: Monad m => (acc -> x -> m (acc, y)) -> acc -> [x] -> m (acc, [y])test-framework Test.Framework.Providers.API No documentation available.
mappendBy :: Monoid b => (a -> b) -> a -> a -> btest-framework Test.Framework.Providers.API No documentation available.
mappend :: Monoid a => a -> a -> aoptparse-applicative Options.Applicative An associative operation NOTE: This method is redundant and has the default implementation mappend = (<>) since base-4.11.0.0. Should it be implemented manually, since mappend is a synonym for (<>), it is expected that the two functions are defined the same way. In a future GHC release mappend will be removed from Monoid.