On 12/22/05, Daniel Carrera <[EMAIL PROTECTED]> wrote: > Paul Moore wrote: > > As I say, I'm not trying to criticize anyone here, but it seems to be > > quite hard to get across to people who have understood and assimilated > > this sort of stuff, just how hard it feels to newcomers. We understand > > the explanations (we do! really! :-)) but even understanding them, we > > are still left with a lack of confidence. It's like being shown a full > > set of carpentry tools, having every one explained, but still reaching > > for the hammer every time and banging something no matter what we're > > trying to do :-) > > I had never heard of mapM, or other -M functions. I can't imagine why > those would be needed. It seems like pointless duplication.
Thanks for confirming my point! FWIW, I don't really see why the -M functions are needed either. It's something to do with the fact that map is for lists, and mapM is for monads, which are a more general type of sequence than a list. But why mapM isn't therefore a superset of map, and so map is redundant, I don't know. (For experts who might want to explain, please note that I can look the differences up. But I can't *picture* the differences well enough to remember them, and hence not *need* to look them up every time, nor can I internalise the differences well enough to use the 2 forms in the correct contexts). Paul. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
