gEDA-dev: gEDA-user: gEDA/gaf capabilities

[Peter Clifton]

On Thu, 2007-11-08 at 08:59 -0600, John Griessen wrote:
> Peter TB Brett wrote:
> > On Wednesday 07 November 2007 17:54:19 John Griessen wrote:
> > 
> >> What do you think of adding hierarchic schematics that handle instances of
> >> subschematics so they are autonumbered, generate a good flat netlist with
> >> long names, and support embedded verilog chunks?
> > 
> > Good idea.  Actually, the big problem here is allowing attributes to have 
> > different values depending on context.
> 
> Are you meaning the context of an instance of a symbol in a drawing, or turning a reference like 0:4
> into a list of instances like 0,1,2,3,4 where you come across the text inside a symbol?

I think this is referring to to the need / desire to be able to
over-ride the attributes of instantiated circuits. Little things like
refdes (still handled just like any other attribute) are best changed
once you instantiate a hierarchical circuit. (Depending on your
numbering schem).

Even if you choose to build a flat name out of a path like
"module2/subckt1/R10", (avoiding clashing R10), you might still like to
alter other attributes for each sub-circuit.

> > This is a non-trivial problem (I've recently been working on datastructures & 
> > algorithms that might allow it to work).

> > The biggest problems are:
> > 
> >  - the current assumption that each text object has only one possible value
> > 
> >  - the lack of a defined "project" concept that would make it easier to "look 
> > up" what the current value to display would be.
> 
> We could benefit multiple ways from making a spec for a project.  So we can use
> that info.
> 
> John G
> 
-- 
Peter Clifton

Electrical Engineering Division,
Engineering Department,
University of Cambridge,
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