I found these articles very valuable in understanding the original motivation for monads and their use for practical development.
Imperative Functional Programming Simon Peyton Jones, Philip Wadler http://research.microsoft.com/pubs/67066/imperative.ps.z Monadic Parser Combinators Graham Hutton http://eprints.nottingham.ac.uk/237/1/monparsing.pdf On Friday, October 26, 2012 9:06:59 AM UTC-7, Brian Craft wrote: > > I've read about four tutorials on monads so far, but it still escapes me. > > In fact, I'm still not sure what problem it solves. I'm familiar with the > problem of having, say, three functions like f(a) -> b, g(c) -> d, h(e) -> > f, which you'd like to chain like f(g(h(x))), but you can't because b is a > different type from c and d is a different type from e. The monad tutorials > all start with a problem like this, but I still can't tell if they're > actually providing a solution, because it appears every monad is specific > to a particular type. E.g. a sequence monad. So, great, I have something > that takes a scalar and returns a sequence. That might solve g(h(x)) if f > is a scalar and c is a sequence by letting me write g(s(h(x))), but it > doesn't solve the whole problem, since I still have f() to worry about. > > So, two specific questions. First, do monads provide a generic solution, > so I can apply f(g(h(x)))? Second, is it the whole point of monads to use > macros so you don't see the glue functions, like s(), in my example? I > mean, we can always write glue functions so we can compose functions with > different input/output types without using monads. What exactly are monads > adding? > > Oh, and one more. If I were to actually use a monad in a piece of > production code, what are the chances that the next person working on the > code would have the faintest idea how it worked? ;-p > -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
