At 21:35 16/07/2002, Ovid wrote: >This is a follow up to my previous email >re: http://www.perlmonks.org/index.pl?node_id=181980. > >Since I'm trying to create "Perlog", a Prolog-like implementation in Perl, >I've run across an >issue which could cause some problems. Specifically, are variadic >(varying number of arguments) >predicates allowed in Prolog? In other words, can someone do this: > > foo( bar, baz ). > foo( bar, quux, camel ).
Yes. they're essential. Your two predicates would be foo/2 and foo/3. >... >If variadic predicates are allowed, what would they be used for? If I can >safely exclude them >from the Perl implementation, this would make life much easier. You certainly cannot exclude them from any implimentation of PROLOG and call it PROLOG - for examples of use, see any number of textbooks. One thought is a routine that calls itself with an argument: if there is no argument, it's the first call. Agh, not clear, sorry, but I've had a very busy weekend, and am still a tad drunk (just married). Good luck -- have you seen the existing Prolog in Perl? Lee
