I'm starting from authorityL
via authorityHostL
to hostBSL
- I know you can combine lenses via
(authorityL . authorityHostL . hostBSL)
but that fails with Couldn't match type ‘Authority’ with ‘Maybe Authority’
. How do I properly deal with the Maybe
here?
You can add a _Just
in between to only focus in on the successful results.
(authorityL . _Just . authorityHostL . hostBSL)
does the trick like it's said in the comments.