[Redirecting to haskell-prime] | In the related work, the "Active Patterns" proposal by Palao et at is missing: | | http://portal.acm.org/citation.cfm?id=232641&coll=portal&dl=ACM | | I thought this work should be included in the list because, I believe, | they were the first to point out that computation should take place | before matching, which was not the case in Wadler's and Burton's | proposals? They also proposed types for patterns. Good point. I've added them. I think the Wadler/Burton stuff did allow for arbitrary computation; it's just that there was no way to do the value-input thing. (Pattern synonyms, on the other hand, do not.) Simon
In my opinion, views are going to make more Haskell more complicated, and from what I have seen so far, for little gain. Maybe a poll should be made to see what features the average Haskeller feels the most in need of. Or what their greatest problems are. Going by the traffic over the previous months, I think that class aliases or extensible records would be higher on most peoples lists than views. Rene.
Rene_de_Visser:
In my opinion, views are going to make more Haskell more complicated, and from what I have seen so far, for little gain.
We need some kind of pattern extension *now* for bytestring matching/views and bit parsing, though. Stuff that's used in large, real world Haskell programs :) -- Don
| > In my opinion, views are going to make more Haskell more complicated, and | > from what I have seen so far, for little gain. | | We need some kind of pattern extension *now* for bytestring | matching/views and bit parsing, though. Stuff that's used in large, real | world Haskell programs :) Would you care to elaborate? After all, pattern guards get quite a lot of the way. Simon
Hello Rene, Wednesday, January 24, 2007, 10:49:06 PM, you wrote:
Going by the traffic over the previous months, I think that class aliases or extensible records would be higher on most peoples lists than views.
i think that proper views is a must for Haskell - "We are keen on abstraction, but pattern matching is so convenient that we break abstractions all the time. It's our dirty little secret. " we need views in order to stop dealing with concrete datatypes and start writing polymorphic functions. just imagine that the following definition sum [x] = x sum (x:xs) = x + sum xs may deal with *anything*, from strict list to patricia tree. isn't that great? -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com
participants (4)
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Bulat Ziganshin -
dons＠cse.unsw.edu.au -
Rene de Visser -
Simon Peyton-Jones