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Date: Sun, 26 Sep 2021 16:12:13 +0200 (CEST)
From: Roland Lutz <rlutz AT hedmen DOT org>
To: "karl AT aspodata DOT se [via geda-user AT delorie DOT com]" <geda-user AT delorie DOT com>
Subject: Re: [geda-user] empty attributes
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On Sat, 25 Sep 2021, karl AT aspodata DOT se [via geda-user AT delorie DOT com] wrote:
> Is there any rationale to not to allow empty attributes
> (except that it isn't implemented) ?

I don't know (this was before my time at the project).

I'm not terribly opposed to supporting empty (as opposed to, unset) 
attributes, but having gEDA treat "refdes=" as an empty attribute would 
introduce a semantic change as text objects in existing schematics may 
then suddenly be interpreted as attributes.

I've long been in favor of making text and attributes different kinds of 
objects, which would remove this ambiguity.  But that (like many other 
potential improvements) would mean an incompatible file format change, 
which I have so far tried to avoid.

Allowing component objects to have an empty refdes would be another, 
different change.  What would it mean for a component to have an empty 
refdes?  If the empty string was treated like any other value, all such 
components would be merged into one package.  Is this useful behavior?

I'm playing with the thought of allowing components to not have any 
refdes= attribute at all in situations where this makes semantic sense, 
e.g., with cascade simulation.  This is a somewhat different concept, 
though, and may not play well together with hierarchy.

Roland