Control.Monad proposal: Add whenJust

[John Wiegley]

>>>>> adam vogt <vogt.adam at gmail.com> writes:

> Another alternative is Data.Foldable.for_, which doesn't clash like
> Data.Foldable.forM_

-1 on a specific whenJust when we have the more general for_ in Foldable.  I
use for_ often for the exact usage proposed here.

-- 
John Wiegley
FP Complete                         Haskell tools, training and consulting
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