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