> You're welcome. Kudos to Luke Wagner who kindly reported the problem > and explained how painful to work around when he was working on a class > project.
Would have been even better if Luke had reported the problem to the mailing list. > I agree with your assessment about the use of `pretend'. I wish my > students never heard of `pretend' :-) You should ask your students to write a one page justification for every "pretend" they use in their program. ;-) >> In Aldor I can use the "keyword arguments" like: >> >> x:Sum(a:Integer,b:Integer) := [b==3] >> >> or equivalently 'union(b==3)' >> >> http://www.aldor.org/docs/HTML/chap13.html#8 >> >> but so far I have not found anything equivalent in any flavor of Axiom. > When you wrote [b == 2], the interpreter understood that you were passing > in value for an optional argument -- much like value for `keyword parameter' > in some other programming languages. I don't like much that double > interpretation of `==' which depends on whether '==' appears at toplevel or > inside expression. > I would rather use a different symbol for `keyword argument', than a fuzzy > interpretation of '=='. Hmm, actually I don't quite understand you here. In union(b==3), the "b==" is in some (other) sense also optional. Only in case where the types of the union are identical, that part would be necessary. Clearly, that are to versions of "optional", but I like the equal syntax using "==" of keyword argument and also for the case of the union above. In fact, if I define a function (sorry, it's again Aldor) foo(b: Integer): Integer == ... then it should be possible to call foo via foo(3) foo(b==7) so also here the "b==" is optional similar to the union case. See AUG Sections 6.3 + 6.4. If I define it via foo(b: Integer == 1): Integer == ... then also foo() will be accepted and be equivalent to foo(1). Could you clarify what exactly you don't like with that? Yes that is overloading of ==, but to me it seems quite intuitive to use "==" for the 2 cases: keyword argument, default value for optional argument. Ralf ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ open-axiom-devel mailing list open-axiom-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/open-axiom-devel
