12 Feb
2005
12 Feb
'05
1:36 p.m.
On Sat, Feb 12, 2005 at 01:08:59PM -0500, Benjamin Pierce wrote:
I have seen lots of examples that show how it's useful to make some type constructor into an instance of Monad.
Where can I find examples showing why it's good to take the trouble to show that something is also a MonadPlus? (I know there are many examples of things that *are* MonadPluses; what I want to know is why this is interesting. :-)
Thanks,
- Benjamin
As a start, free access to countless general functions as soon as you define a MonadPlus instance for your datatype. (Errr, `guard' and `msum', as long as one stays within the Haskell98 standard libraries ;) Groeten, Remi -- Nobody can be exactly like me. Even I have trouble doing it.