Re: about OpenToken

["Marc A. Criley" <mcNOSPAM@mckae.com>]

Lionel Draghi wrote:
> I have no special preferences. I have a simple grammar to implement, and 
>  my main criteria is simplicity.
> When reading OpenToken's doc, I had the impression that a descent 
> recursive parser was easier to write (even if beta).
> That's probably wrong. For example, my grammar is not LL1, and this 
> cause an extra work when using descent parser in OpenToken.
> 
> The fact is that I have spent to much time on this topic.
> I am about to give-up doing the full analysis with OpenToken, and be 
> back to "hand made" analysis. I know that this will becomes a nigthmare 
> when the grammar will grow in complexity, but for now it's still OK.

I tried out OpenToken, and while I think it's probably pretty good for 
nice, rigid grammars, if your needs go beyond that you might need to 
look elsewhere.  (In no way am I criticising OpenToken, there are lots 
of areas where simple, rigid grammars are all that's needed and 
OpenToken does an admirable job with them.)

For XPath In Ada (XIA) (http://www.mckae.com/xia.html) I used AdaGOOP: 
http://unicoi.kennesaw.edu/ase/ase02_02/tools/usafa/adagoop.

It was a little gnarly to set up and use, since it interacts with lex 
and yacc variants called scaflex and scayacc, which I had to dork around 
with to build and use.  Once that was done, though, it worked great 
building me a parser for the XPath grammar.  Though of course I had to 
construct the grammar in the format that AdaGOOP expected, which also 
caused me a few headaches (the grammar, not the format).

Once done, it was done though.  Using AdaGOOP is more work than 
something like OpenToken, but it works well on those more complex 
grammar's, like XPath's, and since I needed XPath querying for the 
pending version of DTraq I was motivated to grind through it and get it 
working.  (And then make XIA available to the Ada community :-)

-- Marc A. Criley
-- McKae Technologies
-- www.mckae.com
-- DTraq - XPath In Ada - XML EZ Out