[Haskell-cafe] Kind of confusing

[Philippa Cowderoy]

On Mon, 2009-05-11 at 20:43 -0400, Anton van Straaten wrote:
> Serious question: what is the significance of the question mark and 
> double question marks in those signatures, or better yet, where can I 
> read about it?
> 

I've forgotten where to find the details (try the GHC manual if you
haven't already?), but IIRC they're part of how GHC handles boxing.

-- 
Philippa Cowderoy <flippa at flippac.org>