gEDA-dev: [pcb] physical layer stack

[Peter Clifton]

On Mon, 2008-02-18 at 21:42 +0100, Stephan Boettcher wrote:
> Stuart Brorson <sdb at cloud9.net> writes:
> 
> > *  Support for footprint rotations at arbitrary angles.
> 
> Yes, please!
> 
> > Dare I suggest that some type of XML or XML-like tree structured
> > format might be a good thing?  

The real lesson I think we could learn from XML is decent name-spacing
for extensibility.

> No, please don't.  Please make it so that I can still use sed and awk
> to edit my layout.  I once used gnumeric to do parts of a layout.

Admitedly editing poses a problem, your parsing tools would need to be
stateful.

XML (and other multi-line free form formats) are write-easy,
read-complex.

You can still happily write out an XML file with printfs, awk, etc..,
but to then re-read a file, you would need to either:

a) Use a proper XML parser
b) Have some guarantees from PCB about the white-space formatting it
uses when saving.

a) isn't totally abhorrent, if you assume this parser lives in PCB, and
PCB were to expose a swiss-army-knife's worth of actions for scripting
with.


As DJ said, at some point we may need to go multi-line, and that means
more parsing complexity. In any case, we need to "invent" this new
format from a data-structures POV. Regarding syntax, if not XML, then
we'd need to invent our own syntax and parsers too.


Peter (Honest I'm not an XML fan-boy) Clifton


-- 
Peter Clifton

Electrical Engineering Division,
Engineering Department,
University of Cambridge,
9, JJ Thomson Avenue,
Cambridge
CB3 0FA

Tel: +44 (0)7729 980173 - (No signal in the lab!)