mzero

[Marcin 'Qrczak' Kowalczyk]

Fri, 18 Jan 2002 05:18:07 -0500, Feuer <feuer@his.com> 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
MonadZero?

-- 
 __("<  Marcin Kowalczyk * qrczak@knm.org.pl http://qrczak.ids.net.pl/
 \__/
  ^^
QRCZAK