Path: utzoo!mnetor!uunet!husc6!sri-unix!teknowledge-vaxc!shardy
From: shardy@teknowledge-vaxc.ARPA (Steve Hardy)
Newsgroups: comp.lang.prolog
Subject: Re: BSI standards
Message-ID: <21375@teknowledge-vaxc.ARPA>
Date: 9 Mar 88 17:33:17 GMT
References: <8803082357.AA01587@decwrl.dec.com>
Organization: Teknowledge, Inc., Palo Alto CA
Lines: 28
In-reply-to: vantreeck@curie.dec.com's message of 8 Mar 88 23:57:05 GMT



vantreeck@curie.dec.com writes:
	            
	RE: Chris Moss' comments on the proposed BSI standards for
	PROLOG syntax.    
                                                                             
	I read the reports also. I'd rather see user defined
	operators left out the standard entirely because it
	complicates the parsing current Edinburgh syntax such
	that it is difficult to write a parser in a low level
	language (which would provide significant space and time
	advantages).

I disagree.  Even though user-defined operators do complicate
prolog syntax, I have found them extremely useful when using
prolog to prototype interpreters for new problem-specific
languages.  We used Prolog to build the first version of the M.1
expert system shell.  Because of user-definable operators, it
was not necessary to to write an parser for M.1 per se.  This
made development much simpler.  Recoding M.1 in C took more
effort than the original development.  Much of the extra cost
was incurred because of the need to write an explicit M.1 parser
in the C version.

DISCLAIMER: Even though I am an employee of Teknowledge, these
are my personal opinions and not those of the company.

Steve Hardy, SHARDY@TEKNOWLEDGE.ARPA, (415) 424-0500