Re: bison-2.4.1 with more graph output

[tys lefering]

On Wed, March 10, 2010 17:27, Akim Demaille wrote:
> Now that Graphviz is free software, with nice software available on all
> the common architectures, what's the point of maintaining VCG output?
Some notes and drawbacks of graphviz dot:

Graphviz dot is not GNU GPL compatible, (parts of) dot
source cannot be integrated re-used in GNU GPL projects.

There is no really working dot graph language parser
GNU GPL available for interface to GNU GPL software.
There is a vcg GNU GPL graph language parser/lexer.

The dot graph language is difficult to parse completely
because parser info is also embedded in strings.
Writing a complete working dot graph parser is
difficult compared to the easy vcg graph language.

The dot tool has limits on maximum output image size
resulting in segfault at too large input graph, now
dot seems to be fixed and scales down the image.

xvcg with -ppmoutput option does indeed generate really
big images without limits and runs stable doing that.

It is easy to add the older vcg driver in bison source,
and does not need maintance, it is bugfree and friendly
to offer users a choice of output graph type,
and no hidden 'vendor lock-in' to non-GPL software.

Also doing a small project vcgview at googlecode
http://code.google.com/p/vcgviewer/
which is a maintained gtk+ gui program to read vcg
and it can read the bison dot graph output too.

Currently adding output to the gnome dia GNU GPL
program to make it possible to edit the graph and
export to several other file types.

This are some reasons to add the older vcg driver
in bison and only few hours work to get that done.

Greetings,
Tys Lefering.