Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!sgi!wdl1!rme
From: rme@wdl1.UUCP (Richard M Emberson)
Newsgroups: comp.lang.c++
Subject: Re: Using OO Languages for Compilers/Interpreters
Message-ID: <3690007@wdl1.UUCP>
Date: 10 Apr 89 13:39:11 GMT
References: <16915@cup.portal.com>
Lines: 21


	A small (but by far the most important point) has been missed.
	Simply to have  yacc or bison produce C++ code is not important,
	but what is important is that their outputs are c++ classes.
	This allows one to have multiple bnf grammers in the same
	executable. (Try linking the output of two yacc grammers in the
	same program - the yacc/bison drivers don't allow multiple
	grammar tables).

	With yacc/bison one dare not use them to make a library because
	any user of the library can not then use yacc/bison in the
	application linking that library.

	The yacc++ I produced from yacc yeilds instances of a class
	(called yacc) defined in a c++ header file. The grammar tables
	are passed in at instance creation. Thus multiple instances can
	exist in the same program and at the same time.

	The same can be done for lex/flex.

								Richard M. Emberson