[Haskell-cafe] Re: [Haskell] Announce: generating free
theorems, online and offline
stefanor at cox.net
Thu Oct 18 20:40:24 EDT 2007
On Thu, Oct 18, 2007 at 08:39:04PM -0400, David Menendez wrote:
> On 10/18/07, Stefan O'Rear <stefanor at cox.net> wrote:
> > On Thu, Oct 18, 2007 at 03:36:01AM -0400, ajb at spamcop.net wrote:
> > > (As an aside: The H98 report still list the right-zero law as being
> > > a law for MonadPlus, even though most MonadPlus instances don't obey
> > > it. That's actually a defect in the report.)
> > All the MonadPlus I can think of (IO,Maybe,) satisfy it. Were you
> > thinking of right distribution?
> "print 1 >> mzero" returns the same result as "mzero" (i.e., it throws
> an exception), but it has different effects.
Oh, hehe. I thought you meant print 1 `mappend` mzero being equal to
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