Add an 'ignore' function to Control.Monad
See http://www.haskell.org/pipermail/libraries/2009-June/thread.html#11880
In short, add a 'ignore :: m a -> m ()' function to Control.Monad. This lets us do things like 'forkIO $ ignore stuff', as opposed to throwing around all sorts of '>> return ()'.
This function could be widely used by many libraries & apps, and has been repeatedly invented and suggested (see the thread). So far no one has said a word against it.
- -- | Convenience function. This is particularly good for 'forkIO' and 'forM_',
-- as they demand return types of 'IO ()', but most interesting IO functions
-- don't return void. So one can wrap them with 'ignore' (essentially a call to 'unit').
ignore :: Functor f => f a -> f ()
ignore = fmap (const ())
Trac metadata
Trac field | Value |
---|---|
Version | 6.10.2 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | libraries/base |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | gwern0@gmail.com |
Operating system | |
Architecture |