Proposal: Add isLeft/isRight to Data.Either

[Bas van Dijk]

On 6 December 2012 23:05, Evan Laforge <qdunkan at gmail.com> wrote:
>>>   - I often use the 'when'-like combinator 'whenJust' in monadic code:
>>>
>>>      whenJust :: Monad m => Maybe a -> (a -> m ()) -> m ()
>>>      whenJust (Just x) a = a x
>>>      whenJust _        _ = return ()
>>
>>
>> +1. whenJust is defined also in Agda.Utils.Monad, should also added to
>> Control.Monad.
>
> Off topic, but I have whenJust in my local library too, and I use it
> all the time.

In a project at work:

$ grep -r whenJust --include=\*.hs . | wc -l
27