On 12/11/2008 05:00 PM, Bill Page wrote: >> Bill Page wrote: >>> The original use case that I presented in another thread involved a >>> different use of "CatOf(R)". If it were possible to refer directly to >>> the category to which a domain belongs, then implementing >>> something similar to Aldor 'extend' would be easy in Spad >>> MyInteger():CatOf(Integer) with >>> ... >>> == Integer add >>> ... > > On Wed, Dec 10, 2008 at 7:02 AM, Ralf Hemmecke wrote: >> OK, that should work if CatOf exists. But now suppose I want >> MyInteger to have a representation that is given by sticks, i.e. the >> integer 5 is represented in MyInteger as 11111 (or rather as the >> string "11111". Now, please implement MyInteger with this >> representation. (You are not allowed to look up the source code >> of Integer in order to find out what exports Integer provides. >> All you have is CatOf. > > Since this is supposed to be an *extension* of Integer the underlying > representation can not change.
Bill, I've already agreed, that as *extension* CatOf might be useful. (But still I would prefer the Aldor "extend" in order to stay compatible. I want a use case that is not connected to extension. > Perhaps I misunderstood your request. :-( Yep. I really meant "representation" instead of "presentation" and I certainly did not want "extension". > Yes, agree. But my point is that 'CatOf' at least makes this much > possible. No question about that. Ralf --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/fricas-devel?hl=en -~----------~----~----~----~------~----~------~--~---
