
----- Original Message ----- From: "Tomasz Zielonka - tomasz.zielonka@gmail.com" Sent: Wednesday, December 07, 2005 8:53 PM
Clean-like _explicit_ uniqueness typing is not what I'm asking for in Haskell.
So you want implicit, automatically inferred uniqueness typing - something that would be even more fragile and sensitive then current Haskell's space problems arising from laziness? ;-)
Maybe it's just my lacking insight, but why should uniqueness inferring be all that fragile? A uniqueness checker can be rather robust, as is demonstrated by the Clean one, so all we'd have to worry about is how to find a good set of supposedly unique node candidates to suggest to the checker. (It certainly would not work well the dumb way, like, trying every single combination out of n^2 possibilities, where n is the total node count.) Whatever suggestion gets through the uniqueness checker, the resulting code can't be consuming more space, slower, or otherwise worse than the one without reusing unique nodes, can it? On the other hand, performance gains thereby seem likely to me.
It might be possible to get extremely fast code out of ghc, but as an overall impression, it's not easy, whilst Clean sort of gives it for granted (well, struggeling with wrongly assigned uniqueness attributes aside).
Well, C sort of gives it for granted too, because it is very difficult to write inefficient, simple, specification-like code. I want to be able to write simple and elegant code, even if it is inefficient!
errr..., could you give me some clue how you'd expect automatically uniqueness detection to deteriorate your coding style? I, for one, don't define elegance in terms of not running too fast. ;) I don't feel very comfortable either with the impact _explicit_ uniqueness attributing has on the ease of coding. Anyway, I am not arguing pro Clean but pro compile time sharing analysis here. To be honest, your reply feels like a counterpart to the likewise questionable monad avoidance in Clean. Regards, zooloo p. s.: Anyone knows what makes your cited mail appear in the list archive as beeing sent from my address? The copy I got to my mailbox is ok. -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.371 / Virus Database: 267.13.12/192 - Release Date: 05.12.2005