Simon Peyton-Jones wrote:
>
> The way it is now, ONE rule, the fold/build rule
> deals with fusion. The others are all there to express things
> in terms of fold and build, AND THEN to return certain common
> patterns of usage for foldr to their familiar mapList and filterList
> forms.
>
> Does that help?
Tremendously. I was thinking that those rules were there becuase the
rule "map f (map g xs) = map (f.g) xs" would simply not work. Now back
to my orignal question:
Why doesn't my "replaceMany (map f l) a = replaceManyMap f l" rule--as
shown in the previous email titled "Rule Question"--behave as expected.
--
Kevin Atkinson
[EMAIL PROTECTED]
http://metalab.unc.edu/kevina/
