Possible, yes. Can you tell us a bit more why you think this is an important requirement (and not just a nice-to-have)?
--Thilo KANO, Yoshinobu wrote: > Thank you for your replies. > This design proposal is fine for me. > Is it possible to implement the multiple inheritances for Apache UIMA in > this way? > > Yoshinobu > > J. William Murdock wrote: >> I think it could be done in a way that was weakly backward compatible >> with the following design: >> >> 1) Leave the existing JCas implementation alone, deprecate it, and >> impose a rule that types that use multiple inheritance cannot be >> accessed via JCas. >> >> 2) Create a new JCas-like mechanism with a new name (e.g., "MultiJCas"), >> that provides the capabilities of JCas and also multiple inheritance (by >> implementing the individual types in the type system as interfaces, and >> generating copies of code when needed, as per EMF). >> >> This is only weakly backward compatible, in that it imposes some serious >> obstacles to anyone hoping to add multiple inheritance to an existing >> component without modifying their code much; however, it would (I >> believe) at least satisfy the minimal requirements that (a) existing >> systems that work would continue to work, and (b) someone building new >> systems can use multiple inheritance. >> >> If an approach like that is taken, then presumably this would be a good >> opportunity to reassess other aspects of the design of JCas based on >> accumulated user experience since the original JCas design (since the >> "MultiJCas" would not need to be backward compatible). >> >> - Bill Murdock (IBM internal UIMA user but not a UIMA framework >> developer or official spokesperson) >> >
