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 | |
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| Blocking | |
| CC | gwern0@gmail.com |
| Operating system | |
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