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!
I cannot help but wonder if it is better to *not* generate type signatures (or at least have an option not to). 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. -- Russell O'Connor http://r6.ca/ ``All talk about `theft,''' the general counsel of the American Graphophone Company wrote, ``is the merest claptrap, for there exists no property in ideas musical, literary or artistic, except as defined by statute.''