Re: [Haskell-cafe] Stupid question, re: overloaded type classes

On Sun, Jan 18, 2009 at 12:43 PM, sam lee wrote:

The following code compiles fine on my ghci

This seems like a bug, you didn't enable overlapping instances and these two instances clearly overlap:

instance Sexpable String where instance Sexpable a => Sexpable [ a ] where

since String is a synonym for [Char]. Although maybe overlapping doesn't get checked until you use the instance? Try adding this line:

test = toSexp "hello"

-- ryan -- ryan