Re: gEDA-user: PCB suggestion

[Magnus Danielson <cfmd@xxxxxxxxxxxx>]

From: Karel Kulhavy <clock@xxxxxxxxxxxxx>
Subject: Re: gEDA-user: PCB suggestion
Date: Fri, 7 Jan 2005 18:48:04 +0000
Message-ID: <20050107184804.GB6276@xxxxxxxxxxxxxxxxxx>

> On Fri, Jan 07, 2005 at 07:34:17PM +0100, Magnus Danielson wrote:
> > From: Al Davis <ad62@xxxxxxxxxxxxxxxx>
> > Subject: Re: gEDA-user: PCB suggestion
> > Date: Fri, 7 Jan 2005 12:27:49 -0500
> > Message-ID: <200501071227.49511.ad62@xxxxxxxxxxxxxxxx>
> > 
> > > On Friday 07 January 2005 11:38 am, Daniel J Wisehart wrote:
> > > > Why not use a neutral standard like XML?  
> 
> Converting this to XML is very easy. You define something like this:
> <XML DTD blahblahblah>
> <my_hexdump_binary_tag length=4>
> f78a6702
> </my_hexdump_binary_tag>
> 
> And then instead of f78a6702 you can place any arbitrary file (adjusting
> the length, of course).
> 
> It's like when they wanted me to write in Pascal in first grade. I knew
> assembler but not pascal. So my pascal program could be:
> begin
> 
> asm
> [assembler code]
> ...
> end
> 
> end.
> 
> This way you wouldn't have to move almost a single finger and it would
> be buzzword-compliant.
> 
> It really isn't hard to make something use XML ;-)

Indeed. But doing something with XML just for the sake of being buzzword
compliant is just pure meaningless. Your example is spot on. XML as such does
not solve anything. What it does give is a certain vehicle in a common way of
structuring things. Basically the same vehicle is available in other formats
such as LISP (EDIF, SDF etc) and VHDL. Actually, a LISP-format parser is even
simpler than a XML parser (I have implemented both). The benefit of XML is the
better support for strange languages and strange charactersets, classically a
problematic area in CAD tools. With a little care could the same benefits be
brought into VHDL or LISP based structures.

What is important is the structure we build onto of the low-level structure of
XML, LISP or VHDL. If it is crap neither XML, LISP or VHDL makes it better, it
just makes it different.

What you can do is creating a good structure and then have XML, LISP and VHDL
based formats for the _same_ structure. Since it is the same structure, you can
convert to the grammar format fitting your needs without loosing any
information, it is just different formats. The LISP structure is sometimes much
better than the XML and VHDL, where as the XML based one is better for some
applications and then the VHDL is better for some. If you want this form of
transparancy, it only takes a little design-effort and it is possible to have
all three of them.

Cheers,
Magnus