On 24 October 2016 at 19:41, Waldek Hebisch <[email protected]> wrote: > Bill Page wrote: >> On 20 October 2016 at 06:16, oldk1331 <[email protected]> wrote: >> > First, the name. Yes, the name "Functor" may lead to >> > confusion, for example, to be mixed with the category >> > theory "Functor". (Well, "Category" has similar problem.) >> > OpenAxiom uses "Functorial", which is similar to "Functor"? >> > I think we can also consider the name "MapCategory". >> >> I am against category names that include the word Category in >> the name. 'SetCategory' is already annoying enough. I think the >> name should reflect the terminology used in the (preferably >> widely accepted) mathematical literature for the relevant concept. > > Well, I agree that we should follow mathematical literature > if possible. However, mathematical terminology is frequently > overloaded and in case of types we need to do some renaming > to disambiguate.
Sure but it seems to me that adding 'Category' in this case is a poor way to disambiguate. I found 88 uses of FooCategory in FriCAS - that is 1/3 of all categories. > And we have cases where we have categories > of objects which behave like some mathematical concept > and a distinguished domain of such category. Current convention > for such cases is Foo for domain and FooCategory for category. > AFAICS there are tens of categories using word Category in > the name and there are good reasons to have more of them. > Only 1/2 of the FooCategories have domains named Foo. 'SetCategory' and 'Set' is typical of this. In the mathematical literature for example the "category of sets" is often denoted in bold face *Set* unfortunately we cant do that in FriCAS, at least not without resorting to unicode symbols. Having inherited most of this from Axiom it is of course a lot to change but I think a much more sensible convention in Axiom might have been simply to just pluralize all category names whether they have FooDomains or not, e.g. Set has Sets Integer has Sets Integer has Rings In any case I do not see any advantage to retaining the original Axiom conventions. > Concerning Functor: principal use is in category theory, > where is means morphism (mapping) between categories. > Clearly the proposed thing is not a functor in such > sense. I don't agree. Given one or more domains and considering all functions over those domains is a good definition of a mathematical category. The 'map' operator is a functor between two such categories. > The word Functor is used in Spad compiler > and using it with other meaning will create confusion. > And while using a different terminology is Spad > compiler is possible the proposed use of Functor > diverges from mathematical practice at least as much > as current use in Spad compiler. > I guess I disagree with that too. I dont know of any other programming language that calls a type constructor a "functor" and it seems much harder to me to relate it to the established use of functor in mathematically category theory. Even in the Axiom itself the use of the term "functor" only seems to appear in the oldest publications. Bill Page. -- 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/fricas-devel. For more options, visit https://groups.google.com/d/optout.
