Re: [boost] Re: [ANN] Spirit C++ parser framework.

From: Greg Colvin (gcolvin_at_[hidden])
Date: 2001-05-23 10:43:35

From: Vladimir Prus <ghost_at_[hidden]>
> 
> I think that to make futher discussion of Spring usefull, we should first of 
> all agree on some points.
> 
> 1. Potential scope
> I have already said that Sprint is unfit for large grammars. The author says 
> "Sure a C++ grammar would most probably choke the parser". It is therefore 
> necessary to establish which grammars are suitable. This can be done through 
> experiment only.

And by understanding, theoretically, just what kind of parser
Spirit is, and what the known performance characteristics of
that kind of parser are.

That said, ease of use is much more important than performance
for the kind of things I imagine Spirit being used for.
 
>     Joel, could you make some more grammars and give performance results 
> compared with traditional parsers, time needed to write and debug parsers, 
> and so on?
>    (Besides, your code fails to compile under g++ 3.0 and bcc 5.5.1). 
> 
> 2.  Syntax
> Proposed syntax has prefix "*" and "+". This is likely to confuse anyone who 
> knows what EBNF is.  Reuben Fries and later David Abrahams have already 
> proposed different syntax. Is it better? I tend to say "yes".

I don't have a strong opinion, but am glad to see the argument
and experimentation towards finding a nice, clean syntax.

> 3. Possible extensions
> Douglas Gregor's idea of compiling Sprint expression looks very neat. I think 
> that if some automata building libary is available, it can be easily 
> accomplished. However, such a library should be completely independent one.

This is cool idea that might well solve the putative performance
problems with Spirit.