On Thu, Jun 17, 2004 at 06:03:31PM -0400, David Menendez wrote: > Stefan Holdermans writes: > > > Well, you've just identified the well-known trade-off between > > abstraction and induction. A language extension involving 'views' [4, > > 1, 3] has been proposed [2] to deal with this issue. > > That proposal for views is eight years old. Has there been any movement > towards implementing it? Did some technical obsticle arise, or have > people simply been busy elsewhere?
I think it was a couple things, Pattern guards were introduced which were conceptually a whole lot simpler and provided a way to do many of the things views did. http://research.microsoft.com/~simonpj/Haskell/guards.html The other thing is that it is unclear whether they are a good idea, I mean, they would probably be useful to some, but as extensions go, they would be a pretty radical change to the language. Many consider the simplicity and consistancy of pattern matching a virtue. Also, the views proposal is 8 years old, I don't know if anyone has thought much about how they would interact with all the other generally accepted language extensions that have happened in the meantime. I think the moral is, don't hold your breath. and learn pattern guards, they are a really really useful and universal extension to the language. John -- John Meacham - ârepetae.netâjohnâ _______________________________________________ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
