Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uwm.edu!wuarchive!sdd.hp.com!ucsd!ucbvax!dog.ee.lbl.gov!pasteur!ICSI.Berkeley.EDU!hws
From: hws@ICSI.Berkeley.EDU (Heinz Schmidt)
Newsgroups: comp.object
Subject: Re: Ideas for OO approaches to parsing
Message-ID: <11471@pasteur.Berkeley.EDU>
Date: 27 Feb 91 00:04:10 GMT
References: <66193@brunix.UUCP>
Sender: news@pasteur.Berkeley.EDU
Reply-To: hws@ICSI.Berkeley.EDU (Heinz Schmidt)
Organization: International Computer Science Institute, Berkeley, CA
Lines: 32

In article <66193@brunix.UUCP>, dkb@cs.brown.edu (Dilip Barman) writes:
|> 
|> 
|> This is somewhat an open-ended question, but I would like suggestions as to
|> what an appropriate way might be to view parsing (from a grammar through
|> to semantics, so I really mean lexical analysis, parsing, and maybe syntax-
|> directed translation) from the OO perspective.  Thanks in advance.
|> 
|> Dilip Barman     dkb@cs.brown.edu
|> Brown University Dept. of Comp. Sci., Box 1910
|> Providence, RI 02912 (401)863-7666 

One way to look at parsing and translations from an OO perspective 
is described in
B.Kraemer,H.Schmidt: Developing Integrated Environments with ASDL
IEEE Software Jan 1989

Particularly we consider syntax-directed translation schemes there:
syntactic categories become classes and translation schemes are
messages that are passed on from objects to their instance variables
(substructures or semantic attributes) and either recursively
construct new structures (translation) or update them (attributation).

If you have parameterized classes in your OO language (or if you can
simulate them) you may write translation rules for list, option and
other extended BNF constructs and take advantage of inheritance. For
instance LIST[X] can inherit from LIST. Typically this saves many
rules. Cf. the article for more details.

--------------------------------------------------------------------------
Heinz W. Schmidt                                     hws@icsi.berkeley.edu
International Computer Science Institute, Berkeley   (415) 642-4274   x175


Brought to you by Super Global Mega Corp .com