Path: utzoo!attcan!uunet!mcvax!unido!ecrcvax!micha From: micha@ecrcvax.UUCP (Micha Meier) Newsgroups: comp.lang.prolog Subject: Re: BSI Prolog terms of reference (coroutining) Message-ID: <532@ecrcvax.UUCP> Date: 11 May 88 07:17:14 GMT References: <831@cresswell.quintus.UUCP> <249@gould.doc.ic.ac.uk> <280@gould.doc.ic.ac.uk> <945@cresswell.quintus.UUCP> Reply-To: micha@ecrcvax.UUCP (Micha Meier) Organization: ECRC, Munich 81, West Germany Lines: 25 Posted: Wed May 11 08:17:14 1988 In article <945@cresswell.quintus.UUCP> ok@quintus.UUCP (Richard A. O'Keefe) writes: >> Since that decision there have been at least two compilers (NU from >> Melbourne and the ECRC product) which appear to have demonstrated >> that the fears were groundless. > >I don't know about the ECRC product. [ ... ] No wonder, it wasn't really famous. ECRC-Prolog has a compiler for MU-Prolog's wait declarations and the overhead introduced by coroutining is minimal - about 5% with naive reverse. In SEPIA, which has another coroutining construct, the delay clauses, this is going to be even less, I suppose. The problem with standardising the coroutining is as with anything else - at least as far as the syntax is concerned, there are already several completely different systems (NU-Prolog, SICStus, Prolog II/III, SEPIA, ...). And what about the semantics? On the other hand, it would be better to standardize it now while there are so few (:-) systems that have this feature. From the efficiency point of view there are no problems, I'm sure. On the contrary, with the coroutining Prolog can solve a lot of problems that cannot be solved without it. --Micha