Control.Monad proposal: Add whenJust

John Wiegley johnw at
Thu May 16 01:03:51 CEST 2013

>>>>> Edward Kmett <ekmett at> writes:

> Personally, I'd be all for just moving Foldable (and Traversable) into the
> Prelude and retiring the monomorphic versions of the functions they supply.
> Both abstractions have born the test of time, and its hard to even envision
> Haskell without them at this point.

> I'm somewhat leery that we coud get this proposal past the "but it makes it
> harder to introduce people to Haskell" backlash, but I'd wholeheartedly
> support it.

A hearty +1 for this.

John Wiegley
FP Complete                         Haskell tools, training and consulting               johnw on #haskell/

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