Control.Monad proposal: Add whenJust

John Wiegley johnw at
Fri May 10 10:52:41 CEST 2013

>>>>> adam vogt <vogt.adam at> 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               johnw on #haskell/

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