GHC support for the new "record" package

[Adam Gundry]

Hi Konstantine,

On 24/01/15 11:55, Konstantine Rybnikov wrote:
> May I suggest something for a syntax (as an option, sorry if it's silly
> or not related)? I really don't like neither "@" or "#" because they
> seem too hacky, meanwhile GHC already has an "accessor" syntax with
> braces { and }, so, might it be an option to have something like:
> 
> ```
> data Foo = Foo { val :: Int }
> data Bar = Bar { foo :: Foo }
> 
> main = do
>   let bar = Bar (Foo 10)
>   print bar{foo{val}}
>   let bar' = bar{foo{val}=10}
>   return ()
> 
> ```
> 
> I think this syntax is 100% understandable for a "newbie". Not sure how
> is it related to lenses though.
> 
> What do you think?

Thanks for thinking about this problem (we certainly need fresh ideas!)
but unfortunately this syntax is already taken by NamedFieldPuns, which
interprets

    foo{val}  ==>  foo{val = val}

so I don't think we can easily use it. I'm still keen to find a better
solution than # or magic imports, though!

Adam


-- 
Adam Gundry, Haskell Consultant
Well-Typed LLP, http://www.well-typed.com/