Marcin 'Qrczak' Kowalczyk
Wed, 23 Jan 2002 11:20:18 +0000 (UTC)

Fri, 18 Jan 2002 05:18:07 -0500, Feuer <> pisze:

> Why is mzero in MonadPlus rather than a separate MonadZero class?

It used to be in MonadZero. In Haskell98 these two classes were merged
into one.

I guess it was to simplify the library and programs using these
classes: they are usually defined together and used together.

Can you give an example of a useful MonadZero instance without
MonadPlus which would be used by some function working on an arbitrary

 __("<  Marcin Kowalczyk *