Path: utzoo!censor!geac!jtsv16!uunet!husc6!bbn!bbn.com!aboulang
From: aboulang@bbn.com (Albert Boulanger)
Newsgroups: comp.lang.lisp
Subject: Re: Code as data (Syntax, macros, run-time compilation)
Message-ID: <40913@bbn.COM>
Date: 5 Jun 89 14:15:13 GMT
References: <31670@sri-unix.SRI.COM> <469@skye.ed.ac.uk> <1028@syma.sussex.ac.uk> <487@skye.ed.ac.uk> <11917@well.UUCP> <9636@polya.Stanford.EDU> <1044@syma.sussex.ac.uk> <378@odi.ODI.COM>
Reply-To: aboulanger@bbn.com
Lines: 20
In-reply-to: dlw@odi.com's message of 5 Jun 89 04:26:37 GMT


In article <378@odi.ODI.COM> Dan Weinreb writes:

  One of the subsequent attempts at MIT was defined and implemented
  successfully.  It was called CGOL, written by Vaughn Pratt, I think
  sometime around 1976.  There is an MIT AI Lab memo that describes it,
  and the source code might very well be available from the AI Lab, for
  all I know.  CGOL apparently never caught on with any user community.
 

We still use this at BBN. In fact the infix reader for Lisp on the
Symbolics uses a reimplementation of CGOL. (This can be extended
somewhat.) We use the Symbolics reimplementation for reading infix
expressions for a rule structure-editor based on presentations. I
found that writing CGOL "productions" much more natural than dealing
with YACC. I think a key element in CGOL for complex parsing is its
notion of sublanguages (which the Symbolics implementation omits).

Albert Boulanger
BBN Systems and Technologies.