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Re: XPath: yes. Which CC to use?

Hi Ann,

Ann Tecklenburg wrote:

> I have reviewed the XPath grammar and think that XPath is a worthy
> addition to any
> XML effort.
>
> XPath appears to be a key utility in several of the other XML specs and
> is a query language on its own.  It appears, as well, that it could be
> some months before we see any more published work from the XQL working
> group and that an XML query language will probably something along the
> lines of  "XPath++"

I'm glad you agree with me on XPath ...,
Also what do u think about XML Update DTD ?
Although it's ODI's proprietary language but it very useful in real life
projects:
we can't only query documents, sometimes we need create and update them too
:-)

> I will be finishing up my current (for pay) project in the next 5 days
> or so and I plan to spend a couple of weeks after that working (if
> possible) on an XPath parser.
>
> The grammar and specifications for XPath are considerably more
> professional than the same for XQL.  (Every existing XPath
> implementation I can find has some problem with it for Ozone's
> purposes.)

Can you explain me, why we can't use , for example IBM's XPath
implementation in LotusXSL ?

> I am considering which Java "compiler-complier" to use.  ANTLR would be
> nice---but it doesn't support the required Unicode AT ALL.  JavaCC is
> not open-source but *will* do the job, and is "freely available".
> SableCC is very nice and is GPL'd although I am not sure how well its
> going to be maintained in the future (SableCC is listed on the GNU site
> and might work).
>
> I can also hand-write a parsing engine---but this makes it more
> difficult to alter and maintain for others in the future.  Under any
> circumstances, the CC must be able to construct a "parse tree".
>
> Speed of the parsing operation is less important than the ease of
> construction and maintenance, for now.
>
> Comments on the choice of a CC technology (wrt to the above) will be
> greatly appreciated.

    I'm not big expert in compilers (I only played with lex and yacc in
college, I tried them for my diploma project LISP Interpreter, but in end I
wrote parser manually :-)
    GMD people seems very happy with JavaCC, and I personally don't think
that every tool you using in Open Source project also must be Open Source,
at end your OS, Java compiler and IDE can be not Open Source ...
    The big advantage of JavaCC over ANTLR (except Unicode support) it's
that JavaCC generate self-contained code - no need in run-time libraries.
    Somebody please check JavaCC license (I'm full zero in license things
:) and if it not require run-time fees, then I vote for JavaCC.

> Once I have finished the parser, I should have an idea what Ozone API's
> I will need to implement the XPath selections.  I suspect that this
> effort will be useful in the larger effort to build a compliant XML
> query language when the final spec gets done.  If not, XPath is still
> useful on its own.
>
> "Speak now or forever hold your peace."

no comments on this :)

Zvi

> Best Wishes,
>
> Ann Tecklenburg
> email:  at@ingenuity-sw.com