Re: [Haskell-cafe] Re: GATD and pattern matching

I don't know whether its a good name or not (the ===), but I have the following in a generic utilities file I have, and I use it every now and then. (===) :: (Typeable a, Typeable b, Eq b) => a -> b -> Bool (===) x y = cast x == Just y (Notice you don't need Eq a in the context) On 11 June 2010 12:51, Ben Millwood wrote:

On Fri, Jun 11, 2010 at 12:46 AM, Felipe Lessa wrote:

...

eqTypeable :: (Typeable a, Eq a, Typeable b, Eq b) => a -> b -> Bool eqTypeable x y = case cast y of Just y' -> x == y' Nothing -> False

...or indeed:

eqTypeable x y = cast x == Just y _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

-- Ozgur Akgun