On Sat, 7 Jul 2012, rocon...@theorem.ca wrote:
On Fri, 6 Jul 2012, Dan Burton wrote:
Following the announcement of lens-family, I'm pleased to announce
lens-family-th 0.1.0.0, a Template Haskell library supplying macros to
generate
lens-family lenses for fields of data types declared with record syntax.
Be warned that currently, type signatures are *not* generated alongside the
lens definitions. Type inference should correctly determine the type of the
generated lenses, but I have structured the library code so that in the
future, type signatures can also be generated. Patches welcome!
http://hackage.haskell.org/package/lens-family-th
I cannot help but wonder if it is better to *not* generate type signatures
(or at least have an option not to).
In data-accessor-template we generate type signatures, also because it
avoids warnings for missing type signatures. However it needed some
fine-tuning before it worked in all cases.
At the moment one can write:
import Lens.Family2.Stock
import Lens.Family2.TH
data Foo a = Foo { _bar :: Int, _baz :: a }
deriving (Show, Read, Eq, Ord)
$(mkLenses ''Foo)
-- | My documentation for the 'bar' lens.
bar :: Lens (Foo a) Int
-- | My documentation for the 'baz' lens.
baz :: LensFamily (Foo a) (Foo a') a a'
I don't know if it is possible to add haddock to functions whose type
signatures are generated by template haskell.
Could the documentation be an argument of mkLenses?
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