[jhickner]

Does lens have a succinct way to traverse a nested data structure where each node is a maybe?

Lenses + Prisms (nicest way I know of in lens):

nested ^? foo . _Just . bar . _Just . baz . _Just

vs. the Maybe monad:

foo >=> bar >=> baz $ nested

[tel]

That's the nicest I know as well. You could use `mapped` instead of `_Just` to make it more generic

    nested ^? foo . mapped . bar . mapped . baz . mapped

Which is also a bit closer to the nature of `>=>` chaining. I actually really like the _Just descent since it makes some of the failure modes for this lens very explicit.

And then it should always be said that the lens has setter properties that the `>=>` chain does not.

[mercurial]

I think that's basically it. You can check out a great example of prisms in the lens-aeson article on FPComplete:

https://www.fpcomplete.com/user/tel/lens-aeson-traversals-pr...