All of the recent talk of support for imperative programming in Haskell makes me really nervous. To be honest, I've always been a bit uncomfortable even with monad syntax. Instead of: do x <- cmd1 y <- cmd2 ... return e I was always perfectly happy with: cmd1 >>= \x-> cmd2 >>= \y-> ... return e Functions are in my comfort zone; syntax that hides them takes me out of my comfort zone. In my opinion one of the key principles in the design of Haskell has been the insistence on purity. It is arguably what led the Haskell designers to "discover" the monadic solution to IO, and is more generally what inspired many researchers to "discover" purely functional solutions to many seemingly imperative problems. With references and mutable data structures and IO and who-knows-what-else to support the Imperative Way, this discovery process becomes stunted. Well, you could argue, monad syntax is what really made Haskell become more accepted by the masses, and you may be right (although perhaps Simon's extraordinary performance at OSCOM is more of what we need). On the other hand, if we give imperative programmers the tools to do all the things they are used to doing in C++, then we will be depriving them of the joys of programming in the Functional Way. How many times have we seen responses to newbie posts along the lines of, "That's how you'd do it in C++, but in Haskell here's a better way...". I hope I don't start a flame war with this post -- I'm just expressing my opinion, which admittedly is probably regressive rather than progressive :-). -Paul -- Professor Paul Hudak Department of Computer Science Office: (203) 432-1235 Yale University FAX: (203) 432-0593 P.O. Box 208285 email: paul.hudak@yale.edu New Haven, CT 06520-8285 WWW: www.cs.yale.edu/~hudak