> On Fri, Jun 21, 2002 at 12:50:21PM +0100, Simon Peyton-Jones wrote: > > | From: Jon Fairbairn [mailto:[EMAIL PROTECTED]] > > | Sent: 20 June 2002 16:27 > > | To: Simon Peyton-Jones > > | Subject: Library report, monad zero laws > > | > > | The old report used to include > > | > > | m >> zero = zero > > | zero >>= m = zero > > | m ++ zero = m > > | zero ++ m = m > > | > > | after the other monad laws. Now mzero and mplus are in the > > | library, shouldn't there be some mention of these laws there? > > | I'd be particularly keen to see a remark about > > | > > | _|_ >> zero > > | > > | inevitably being _|_ > > Would you put that next to m >> zero = zero ?
Well, that's rather the point. At the moment the library report just says "The class methods mzero and mplus are the zero and plus of the monad.", which implies m >> zero = zero, but it can't be. -- Jón Fairbairn [EMAIL PROTECTED] 31 Chalmers Road [EMAIL PROTECTED] Cambridge CB1 3SZ +44 1223 570179 (after 14:00 only, please!) _______________________________________________ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
