On Saturday 07 February 2009 12:11:29 pm Gregg Reynolds wrote:
I had a monadic revelation at about 3 am. The answer to the question "what is an IO value, really?" is "who cares?" I just posted a blog entry discussing how CT found it's way from Moggi into Haskell at http://syntax.wikidot.com/blog (hence the title; Moggi as functor). It addresses the question of what such things are and why Moggi's insight is so brilliant. Feedback welcome, but please remember this is coming from a non-mathematician who likes to write. If you find anything there that outrages your inner Russell, please correct me, but be gentle.
As far as I know, Moggi didn't really have anything directly to do with Haskell. He pioneered the idea of monads being useful in denotational semantics. But it was Wadler that recognized that they'd be useful for actually writing functional programs (see his "The Essence of Functional Programming"). So one might say that it was his doing that brought monads to Haskell proper. -- Dan