Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!elroy.jpl.nasa.gov!jpl-devvax!lwall
From: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Newsgroups: comp.lang.perl
Subject: Re: expression evaluation
Message-ID: <10522@jpl-devvax.JPL.NASA.GOV>
Date: 24 Nov 90 20:48:51 GMT
References: <9171@pasteur.Berkeley.EDU>
Reply-To: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Organization: Jet Propulsion Laboratory, Pasadena, CA
Lines: 21

In article <9171@pasteur.Berkeley.EDU> jhh@sprite.Berkeley.EDU (John H. Hartman) writes:
: 
: I'd like to write a Perl program that evaluates expressions with the
: following grammar:
: 
: expr -> expr op expr
: expr -> ( expr )
: expr -> 1
: expr -> 0
: op -> ||
: op -> &&
: 
: 
: Does anyone have a program that does something similar?  

My brother-in-law Mark Biggar (who did the big* packages) is about to
release a parser generator that takes an ll(1) grammar and turns it
into a recursive descent tokener/parser.  The above grammar isn't ll(1)
but could be turned into one.

Larry