Re: Lark 1.0 final beta and Larval 0.8

Peter Murray-Rust (peter@ursus.demon.co.uk)
Wed, 07 Jan 1998 01:08:50


At 11:17 05/01/98 -0800, Tim Bray wrote:
>This isn't finished yet, but I am uncomfortable about the fact that
>for the last couple of months, there has not been a java-language XML
>syntax-checker that is really very close to the spec. So, at
>
> http://www.textuality.com/Lark/

Great. I have downloaded and hope to hack it tomorrow.

>
>I have placed the Lark 1.0 final beta, and release 0.8 of Larval,
>a validating XML processor based on Lark.
>These class files have been compiled with Microsoft VJ++1.1 and
>tested with Microsoft JView and with Sun's Java from JDK 1.1.3.
>At the moment, if I compile with the Sun fastjavac, then neither
>the Sun nor Microsoft java interpreters can use the resulting
>class files. Admittedly, Lark.java and Larval.java are a pretty
>severe strain on a compiler; on the other I know about some pretty
>egregious violations of the Java language spec that will get by
>both of those compilers. I suspect that my current problem with
>fastjavac is as likely to be me breaking some rule about what can
>be in a static string (J++ is forgiving) as it is a compiler bug.

I have had a problem with jvc compiling complex code (a matrix
diagonalisation converted from Fortran) where it threw an internal
compiler error. And the Lark problem where I have to compile with jvc
rather than javac. I imagine that it's a good idea in general to run code
through as many compilers as possible and I make sure that mine works with
jvc and javac.

[...]

>The validation implementation is pretty naive. Rather than compiling
>tables, Larval builds a data structure more or less isomorphic to
>the declaration in the DTD, and then laboriously pokes around in it
>every time it sees a start/end tag. I think it proves that (a) a
>naive implementation of validation can be done, and (b) this isn't

Good!

>the right way to do it in the long-term. However, it's nowhere
>near as slow as I expected, and is good enough to be useful already
>in debugging XML documents.

This will also be useful in editing XML I hope.

P.

Peter Murray-Rust, Director Virtual School of Molecular Sciences, domestic
net connection
VSMS http://www.nottingham.ac.uk/vsms, Virtual Hyperglossary
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