[incomprehensible (not necessarily wrong!) stuff about polynomials, rings, modules over Z and complaints about the current prelude nuked] --- Marcin 'Qrczak' Kowalczyk pisze ---
Please show a concrete proposal how Prelude classes could be improved.
--- Jerzy Karczmarczuk repondre ---
I am Haskell USER. I have no ambition to save the world. The "proposal" has been presented in 1995 in Nijmegen (FP in education). Actually, it hasn't, I concentrated on lazy power series etc., and the math oriented prelude has been mentioned casually. Jeroen Fokker presented similar ideas, implemented differently.
I'm afraid all this discussion reminds me the one we had a year or two ago. At that time the mathematically inclined side was lead by Sergei, who to his credit developed the Basic Algebra Proposal, which I don't understand, but many people seemed to be happy about at that time. And then of course nothing happend, because no haskell implementor has bitten the bullet and implemented the proposal. This is something understandable as supporting Sergei's proposal seem to be a lot of work, most of which would be incompatible with current implementations. And noone wants to maintain *two* haskell compilers within one. Even if this discussion continues and another brave soul develops another algebra proposal I am prepared to bet with both of you in one years supply of Ben and Jerry's (not Jerzy :)!) icecream that nothing will continue to happen on the implementors side. It is simply too much work for an *untested* (in practice, for teaching etc) alternative prelude. So instead of wasting time, why don't you guys ask the implementors to provide a flag '-IDontWantYourStinkingPrelude' which would give you a bare metal compiler with no predefined types, functions, classes, no derived instances, no fancy stuff and build and test your proposals with it? I guess the RULES pragma (in GHC) could be abused to allow access to the primitive operations (on Ints), but you are still likely to loose much of the elegance, conciseness and perhaps even some efficiency of Haskell (e.g. list comprehensions), but this should allow us to gain experience in what sort of support is essential for providing alternative prelude(s). Once we learnt how to decouple the prelude from the compiler, and gained experience with alternative preludes implementors would have no excuse not to provide the possibility (unless it turns out to be completely impossible or impractical, in which case we learnt something genuinely useful). So, Marcin (as you are one of the GHC implementors), how much work would it be do disable the disputed Prelude stuff within the compiler, and what would be lost? Laszlo [Disclaimer: Just my 10 wons. This message is not in disagreement or agreement with any of the previous messages]