List comprehensions

Jon Fairbairn Jon.Fairbairn@cl.cam.ac.uk
Fri, 31 Jan 2003 00:41:28 +0000


On 2003-01-30 at 11:08GMT Ross Paterson wrote:
> On Thu, Jan 30, 2003 at 11:41:49AM +0100, Rijk J. C. van Haaften wrote:
> > Recently, I came accross this
> > expression:
> > [ x + y | x <- xs | y <- ys ]
> > 
> > As far as I can see (Haskell Report),
> > this is not allowed by the haskell 98
> > standard. So I assume it to be an ex-
> > tension. Where can I find information
> > about this?
> 
> It's not Haskell 98, but is implemented in GHC and Hugs (with extensions
> turned on).

As far as I can tell ghc 5.04 accepts this without
complaint. Is this a bug, or should I pass some argument to
turn extensions off?

  Jón


-- 
Jón Fairbairn                                 Jon.Fairbairn@cl.cam.ac.uk