Re: [gobo-eiffel-develop] Object-oriented byte-codes for regularexpressions?

[Eric B. <er...@go...>]

Colin Paul Adams wrote:
>>>>>> "Eric" == Eric Bezault <er...@go...> writes:
> 
>     >> So I should wrap a C library then?
> 
> I wasn't actually serious about that

Yes, I knew that you would prefer assembly code ;-)

> 
>     Eric> What I had in mind is more something like EiffelParse
>     Eric> vs. geyacc.
> 
> Can you expand on that statement please?

I don't know the current status, but 10 years ago using
EiffelParse to write parsers (yooc was there to help) produced
very slow parsers. EiffelParse has a very nice object-oriented
design for the parser implementation. I don't know if it's
related on not, but it's slow.

On the other hand, geyacc was written to produce ugly
non-object-oriented parsers, based on zillions of integers
put in tables or used in inspect statement. The resulting
parser looks more or less what the parser would look like
if generated by yacc in C, but with an Eiffel syntax.
I don't remember the exact results of the benchmarks, but
parsers generated by geyacc were much faster than EiffelParse.

Of course the geyacc solution is usable only if the clients
of the generated parsers don't have to dive into the code
of the parsers themselves. We should see it as a black-box.

I think that a regexp library has the same criteria. That's
typically something that clients want to be fast. And clients
see it as a black-box (not that many people decide to dive
into the code of regexp implementation to understand how it
works).

-- 
Eric Bezault
mailto:er...@go...
http://www.gobosoft.com