> I don't understand. If I programmed a domain Pair(A, B) and made its Rep > equal to > > Record(first: A, second: B) > > would the compile produce something more complicated than a cons pair > for the representation?
First, functions in Pair can use Rep.first, Rep.second, that is fast. Outside Piar, 'first pair' might be a SPADCALL, but that can be optimized by lisp macro: first pair == QCAR(pair)$Lisp > Note that one can also implement "no duplicates" by just adding a new > (key, value) pair in front of the list and never show duplicate keys in > the output (although they are still there in the representation). Only > when a key is deleted, then *all* keys have to be removed from the > datastructure. > It's certainly a question of how exactly AssociationList should behave. > That is why a proper specification is needed. Stop thinking AlistAgg as a table, think it as a list. AlistAgg is Lisp's alist, it allows duplicates. > i.e., for most cases Table is implemented as an AssociationList with > linear access time. > > So if we agree on duplicate keys in AssociationList, then Table might be > in danger. I think in most cases Table is not implemented as ALIST, I checked that. Table only exports TableAgg, if you use only functions from TableAgg, you can't create a duplicated key, so there's no problem using ALIST as Rep of Table. > But it seems that you cannot easily remove TableAgg from AListAgg, > because, ALIST is used as the implementation of Table as I wrote in my > last mail. Yes it can. Simply move the TableAgg specific functions from ALIST to Table (we might need a layer there). And that's my next step. -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To unsubscribe from this group and stop receiving emails from it, send an email to fricas-devel+unsubscr...@googlegroups.com. To post to this group, send email to fricas-devel@googlegroups.com. Visit this group at https://groups.google.com/group/fricas-devel. For more options, visit https://groups.google.com/d/optout.
