Does everyone all agree that "MapCategory" is a proper name? There's a problem when implementing Haskell's Applicative:
Applicative A exports signature: ap : (A(S->S), A(S)) -> A(S) -- % is A(S) First, you can't express A(S->S) in category definition. Second, for a specific domain, compiler doesn't accept type A(S->S). (For example, in domain List, you can't use List(S->S) .) In interpreter, for List, ap can be defined as this, with or without type: ap(f:List(INT->INT),x:List(INT)):List(INT) == concat map(y+->map(y,x),f) ap(f,x) == concat map(y+->map(y,x),f) Note that in general it should use function 'join : M(M a) -> M a' instead of concat, and this signature also can not be expressed in category. I think these 2 limitations are not fundamental and can be worked out. -- 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.
