[9fans] OT: DTD to yacc spec?

[9fans] OT: DTD to yacc spec?

[Laura Creighton]

I know somebody who used pyRXP to do this.
http://www.reportlab.org/pyrxp.html

Unfortunately, I cannot remember who it was, but I can ask my
buddies at reportlab if it is of interest ....

Laura Creighton

Re: [9fans] OT: DTD to yacc spec?

[kazumi iwane]

> I know somebody who used pyRXP to do this.
> http://www.reportlab.org/pyrxp.html

I regret that I don't speak python (yet!). Thank you anyway.

-- kazumi

[9fans] OT: DTD to yacc spec?

[kazumi iwane]

I've looked at several xml parsers and I found them all to
be too general. They want to be all-encompassing parsers
for any DTDs that are thrown at them.

In my area of applications, however, systems exchange
XML files conforming to a particular DTD; once the DTD
is agreed upon, we need no generality. Instead we need
speed and space efficiency.

I guess I am looking for a tool that can convert a DTD into
a good old yacc grammar spec (I would still need to provide
actions, though). Does anybody know of such a tool?

-- kazumi

Re: [9fans] OT: DTD to yacc spec?

[plan9]

Apologies for keeping the off trackness.

kazumi writes:
> I've looked at several xml parsers and I found them all to
> be too general. They want to be all-encompassing parsers
> for any DTDs that are thrown at them.
>
> In my area of applications, however, systems exchange
> XML files conforming to a particular DTD; once the DTD
> is agreed upon, we need no generality. Instead we need
> speed and space efficiency.
>
> I guess I am looking for a tool that can convert a DTD into
> a good old yacc grammar spec (I would still need to provide
> actions, though). Does anybody know of such a tool?

Oh, how great it is to know that I'm not alone.  Ever since I have
been exposed to XML and its parsers have I wondered about their
weirdness.  They never looked like parsers to me, more like toolkits
to help write a generic XML editor or display system.

I would absolutely love to have a parser generator that takes a DTD or
schema and produces a parser to read XML only for that one definition.
All I have encountered so far are "validating" parsers that seem to
make XML file interchange even harder, as the DTD or schema has to be
provided from the outside.

I guess this kind of thing is just a fallout from discussions that end
up in "we have all these homegrown file formats for configuration,
user preferences, application private data, ..., and it must be so
much hassle keeping all of that coded up nicely; we need to clean this
up pronto, and the only recognised way of doing it is by using XML;
our life will become so much simpler, as there are so many tools out
there to help with this." Sniff.

Robby

Re: [9fans] OT: DTD to yacc spec?

[David Tolpin]

> >
> > I guess I am looking for a tool that can convert a DTD into
> > a good old yacc grammar spec (I would still need to provide
> > actions, though). Does anybody know of such a tool?
>
> Oh, how great it is to know that I'm not alone.  Ever since I have
> been exposed to XML and its parsers have I wondered about their
> weirdness.  They never looked like parsers to me, more like toolkits
> to help write a generic XML editor or display system.
>
> I would absolutely love to have a parser generator that takes a DTD or
> schema and produces a parser to read XML only for that one definition.
> All I have encountered so far are "validating" parsers that seem to
> make XML file interchange even harder, as the DTD or schema has to be
> provided from the outside.

An XML parser is like lex(1), it performs tokenization on the level
of XML. When you want a grammar-driven processing of an XML file,
you can convert DTD to a yacc grammar with awk and use an XML parser
to implement yylex.

Additionally a number of tools exists to generate code from schemata,
such as RelaxNGCC (http://relaxngcc.sourceforge.net/). Since Relaxб═NG
can be generated from DTD by Trang,
http://thaiopensource.com/relaxng/trang.html , it solves your problem.

One of many tools in C which match your description is at
http://flexml.sourceforge.net/ . There are also many others around.

David Tolpin
http://davidashen.net/

Re: [9fans] OT: DTD to yacc spec?

[kazumi iwane]

> One of many tools in C which match your description is at
> http://flexml.sourceforge.net/ . There are also many others around.

Thank you for the info. FleXML seems most close to what I had in
mind. I will look into it. Why they had to use XML for action
definitions,
I don't know.

-- kazumi

Re: [9fans] OT: DTD to yacc spec?

[kazumi iwane]

> I guess this kind of thing is just a fallout from discussions that end
> up in "we have all these homegrown file formats for configuration,
> user preferences, application private data, ..., and it must be so
> much hassle keeping all of that coded up nicely; we need to clean this
> up pronto, and the only recognised way of doing it is by using XML;
> our life will become so much simpler, as there are so many tools out
> there to help with this." Sniff.

Sounds very familiar. We use XML only because everybody else
does. This silly reasoning hardly justifies the cost of dealing with
complexity forced upon us by XML parsers.

-- kazumi

Re: [9fans] OT: DTD to yacc spec?

[boyd, rounin]

> I've looked at several xml parsers and I found them all to
> be too general. They want to be all-encompassing parsers
> for any DTDs that are thrown at them.

oxymoron.

there are better ways.