From: Steven Jenkins <steven.jenkins@...>
Date: 2005-11-04T23:08:03+09:00
Subject: Re: any good racc examples that parse from an IO instead of a String?

Eric Mahurin wrote:
> I wanted to compare how the my grammar project compares against racc in
> terms of performance. I have yet to find an example that parses from an IO.
> Everything I've found so far parses from a String. Seems kind of silly if
> racc has to read in the whole file before parsing - or everybody is doing it
> that way. Maybe because people write there lexers based on regexes which
> require Strings (I noticed discussions about this on another thread).

I don't understand the question. The parser operates on a token stream, 
neither String nor IO.

I have a real (but arcane) Racc application; you're welcome to see it. 
(It's a reverse-engineered parser for the export format of a commercial 
system engineering tool.) The lexer pushes tokens onto an array and the 
parser shifts from it. The lexer does read the entire file into memory 
before parsing, but that could be trivially changed by running the lexer 
in a separate thread and using a Queue for the token stream.

Steve