Proposal: add Control.Monad.whenJust ∷ (Monad m) ⇒ Maybe α→(α→ m ()) → m ()

Mikhail Vorozhtsov mikhail.vorozhtsov at
Thu Dec 1 07:07:08 CET 2011

On 11/30/2011 11:26 PM, Evan Laforge wrote:
> On Tue, Nov 29, 2011 at 11:11 PM, Liyang HU< at>  wrote:
>> This particular pattern crops up a lot for me. Does it for anyone else?
> Yep, I have that in my personal library, and use it fairly often.
> I prefer it to Foldable.forM_ because it's explicit about the type it
> takes, forM_ sounds too much like a loop.
Well, it is a loop over collection, which in the case of Maybe can 
contain at most one element.

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