Robert Dockins wrote:
Actually, I've been wondering about this. If my understanding is correct, Haskell lists are basicly singly-linked lists of cons cells (is that correct?) A simple (I think) thing to do would be to make the lists doubly-linked and circular. That would let us do nice things like have O(1) primops for reverse, tail, (++) and other things that access lists at the end. However, I'm still pretty new to FP in general, so I don't know if there are any theoretical reasons why something like this couldn't work. Obviously lazy and infinite lists add some wrinkles, but I think it could be worked through.
BTW can you give some references to these known techniques?
Don't know if this is exactly what you are looking for, but I found these articles quite interesting. http://www.stud.tu-ilmenau.de/~robertw/dessy/fun/ http://www.stud.tu-ilmenau.de/~robertw/dessy/fun/democratic/ Greg Buchholz