Ralf Hemmecke <[EMAIL PROTECTED]> writes: > >> I must say, no matter whether it is syntactic sugar or not, a > >> definition of the form > >> > >> (*) D(P : Polynomial (R : Ring)) : ... == ... > >> > >> would confuse me. How am I supposed to used that? Should I write > > Boy, my first email this morn had a few more typos than I would have > > liked. Ill try to ensure I have at least one cup of coffee before > > sitting down to write an email :) > > In the scheme I was (trying, badly) to suggest would have looked as > > follows: > > D(p : Polynomial (R : Ring)) : ... == .. > > Notice the p is lowercased, hense denoting a domain value. > > Oh, you would like to turn a convention into a language construct. I > have programmed enough in Aldor to be able to say, that is a bad thing. > Note that + or 1 can be used to denote identifiers in Aldor. Are they > lower or upper case?
Im not going to try and defend the idea, as I feel I can work with simpler notions. But 1 and + would be considered value identifiers. > > >> Now suppose I define > >> > >> define MyPolyCat:Category == Polynom(Integer) with ... > >> MyPoly: MyPolyCat == add ... > >> > >> Now can I write > >> > >> D MyPoly > >> > >> ??? (Note that it doesn't exactly match your pattern (*).) > >> Or should I rather write > >> > >> D(Integer, MyPoly) > >> > >> even with just the definition (*)? > >> > >> I cannot see that I would like such sugar. > > Ok, sorry for the confusion. Using your example, I would have > > written: D(P : Polynom(R : Ring)) ... > > Then yes, you would write `D MyPoly'. > > So then let's go on. How would MyPoly now tell you that it is defined > over Integer? Its type is MyPolyCat (there is still no Integer). So in > order to find out that the Argument I give you fits your pattern, you > have to look inside the category hierarchy. OK, should be doable, but > is more than just pattern matching. Still, I don't like it. > > Suppose you would have something like > > DAldor(R: Ring, D1: CatA(R), D2: CatB(R)): ... > > Then your way would probably lead to > > DSteve(D1: CatA(R: Ring), D2: CatB(R: Ring)): ... > > That is needless doubly typing "Ring" and even worse, it is ambiguous. > Who does tell me that this definition would be equal or different from > > DSteve(D1: CatA(R: Ring), D2: CatB(S: Ring)): ... > > I must say, if you modify the language in that direction, I am the > first who doesn't follow your direction. No, my way would be: DSteve(D1: CatA(R: Ring), D2: CatB(R)): ... However, I need to explore the use tuples exclusively to lift types otherwise hidden by sope into an enclosing context. I suspected that type patterns would be generally useful but I like the simplicity of Martins approach and will try to work with that. > > Ralf Thanks, Steve _______________________________________________ Axiom-developer mailing list Axiom-developer@nongnu.org http://lists.nongnu.org/mailman/listinfo/axiom-developer
