On Fri, 16 Feb 2001, Jerzy Karczmarczuk wrote:
[..]
fm _ z [] = return z fm g z (a:aq) = g z a >>= \y->fm g y aq
When I started correcting the exam, I thought I would jump out of the window. First 30 copies: The type of fm is
ff -> b -> [c] -> b
(with an appropriate constraint for the functional type ff). The result had for them the same type as the type of z.
My inquiry proved beyond any doubt that my students are so conditioned by "C", that despite the fact that we worked with monads for several weeks, they *cannot imagine* that "return z" may mean something different than the value of "z".
Any suggestions?
Not that it would help you much, but I also think that return is a rather confusing name for what might otherwise be called liftM0. Regards, Andreas. ------------------------------------------------------------------------ Andreas Gruenbacher gruenbacher@geoinfo.tuwien.ac.at Research Assistant Phone +43(1)58801-12723 Institute for Geoinformation Fax +43(1)58801-12799 Technical University of Vienna Cell phone +43(664)4064789