forM_

forM_ :: (Foldable t, Monad m) => t a -> (a -> m b) -> m ()

forM_ is mapM_ with its arguments flipped. For a version that doesn't ignore the results see forM. forM_ is just like for_, but specialised to monadic actions.

form_ :: Term arg result => arg -> result

lucid Lucid.Html5, lucid2 Lucid.Html5

form element or form attribute

forM_ :: (Foldable t, Monad m) => t a -> (a -> m b) -> m ()

rio RIO.Prelude

forM_ is mapM_ with its arguments flipped. For a version that doesn't ignore the results see forM. As of base 4.8.0.0, forM_ is just for_, specialized to Monad.

forM_ :: (Monad m, Vector v a) => v a -> (a -> m b) -> m ()

rio RIO.Vector

O(n) Apply the monadic action to all elements of a vector and ignore the results. Equivalent to flip mapM_.

forM_ :: Monad m => Vector a -> (a -> m b) -> m ()

rio RIO.Vector.Boxed

O(n) Apply the monadic action to all elements of a vector and ignore the results. Equivalent to flip mapM_.

forM_ :: (Monad m, Storable a) => Vector a -> (a -> m b) -> m ()

rio RIO.Vector.Storable

O(n) Apply the monadic action to all elements of a vector and ignore the results. Equivalent to flip mapM_.

forM_ :: (Monad m, Unbox a) => Vector a -> (a -> m b) -> m ()

rio RIO.Vector.Unboxed

O(n) Apply the monadic action to all elements of a vector and ignore the results. Equivalent to flip mapM_.

forM_ :: (MonoFoldable mono, Applicative m) => mono -> (Element mono -> m ()) -> m ()

mono-traversable Data.MonoTraversable.Unprefixed

Synonym for oforM_

forM_ :: (Contiguous arr, Element arr a, Element arr b, Applicative f) => arr a -> (a -> f b) -> f ()

contiguous Data.Primitive.Contiguous

forM_ is mapM_ with its arguments flipped. For a version that doesn't ignore its results, see forM.

forM_ :: MonadParallel m => [a] -> (a -> m b) -> m ()

monad-parallel Control.Monad.Parallel

Like forM_, but applying the function to the individual list items in parallel.

forM_ :: (Container t, Monad m) => t -> (Element t -> m b) -> m ()

universum Universum.Container Universum.Container.Class

Constrained to Container version of forM_.

>>> forM_ [True, False] print
True
False

forM_ :: (Monad m, Vector v a) => Vector v n a -> (a -> m b) -> m ()

vector-sized Data.Vector.Generic.Sized

O(n) Apply the monadic action to all elements of a vector and ignore the results. Equivalent to flip mapM_.

forM_ :: (Monad m, Prim a) => Vector n a -> (a -> m b) -> m ()

vector-sized Data.Vector.Primitive.Sized

O(n) Apply the monadic action to all elements of a vector and ignore the results. Equivalent to flip mapM_.

forM_ :: Monad m => Vector n a -> (a -> m b) -> m ()

vector-sized Data.Vector.Sized

O(n) Apply the monadic action to all elements of a vector and ignore the results. Equivalent to flip mapM_.

forM_ :: (Monad m, Storable a) => Vector n a -> (a -> m b) -> m ()

vector-sized Data.Vector.Storable.Sized

O(n) Apply the monadic action to all elements of a vector and ignore the results. Equivalent to flip mapM_.

forM_ :: (Monad m, Unbox a) => Vector n a -> (a -> m b) -> m ()

vector-sized Data.Vector.Unboxed.Sized

O(n) Apply the monadic action to all elements of a vector and ignore the results. Equivalent to flip mapM_.

forM_ :: (Source r a, Index ix, Monad m) => Array r ix a -> (a -> m b) -> m ()

massiv Data.Massiv.Array

Just like mapM_, except with flipped arguments.

Examples

Here is a common way of iterating N times using a for loop in an imperative language with mutation being an obvious side effect:

>>> import Data.Massiv.Array as A

>>> import Data.IORef

>>> ref <- newIORef 0 :: IO (IORef Int)

>>> A.forM_ (range Seq (Ix1 0) 1000) $ \ i -> modifyIORef' ref (+i)

>>> readIORef ref
499500

forM_ :: (Mappable col, Applicative m, Monad m) => col a -> (a -> m b) -> m ()

foundation Foundation.Collection

forM_ is mapM_ with its arguments flipped. For a version that doesn't ignore the results see forM.

forM_ :: Monad m => UnfoldlM m input -> (input -> m ()) -> m ()

deferred-folds DeferredFolds.UnfoldlM

Same as mapM_ with arguments flipped

forM_ :: (Context a, Monad m) => Matrix a -> (a -> m b) -> m ()

matrices Data.Matrix Data.Matrix.Storable Data.Matrix.Unboxed

forM_ :: (Vector v a, Monad m) => Matrix v a -> (a -> m b) -> m ()

matrices Data.Matrix.Generic

forM_ :: (Generator c, Monad m) => c -> (Elem c -> m b) -> m ()

reducers Data.Generator.Combinators