I want to play around with the Lens
library a bit. I've loaded it into GHCi and created a record data type with the appropriate underscores:
> data Foo a = Foo {_arg1 :: Int, _arg2 :: [a]}
I would like to make the lenses for Foo
using the makeLenses
template. I would like to do this without needing to read through the entire set of Template-Haskell docs.
What incantation can I type in at the GHCi prompt to get this to work?