:: (Foldable t, Monad m) => (a -> m b) -> t a -> m () package:base-compat-batteries

Map each element of a structure to a monadic action, evaluate these actions from left to right, and ignore the results. For a version that doesn't ignore the results see mapM. mapM_ is just like traverse_, but specialised to monadic actions.

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.