12 Feb
2005
12 Feb
'05
2:10 p.m.
On Sat, Feb 12, 2005 at 01:47:06PM -0500, Benjamin Pierce wrote:
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 ;)
Yes, those are good examples. (But I'd still be interested to see some of the countless others... :-)
Thanks,
- Benjamin
Network.URI and Data.Generics also define a few functions which require MonadPlus instances. Can't find anything else right now. Nor do I know of the (countless? ;)) more theoretical reasons to define instances. -- Nobody can be exactly like me. Even I have trouble doing it.