Re: Does PATH need a new attribute?

To focus on the core issue (and not the specific example Thomas provided),
the question really comes down to:

Can we make it possible in SVG to create stroke effects that apply to only
certain segments in a complex shape?

In CGM, as I understand it, this particular on/off stroking effect is
included within the basic path geometry instructions.  However, there are
many more general cases as well.  In data viz/d3, we often get people
asking if it is possible to color one section of a polyline-type path
differently than the others.

The solution that currently exists is the same solution that Thomas is
using for his CGM conversions: create two (or more) paths, one to draw the
fill, and the other(s) to draw the line segments.  But as Thomas pointed
out, that loses the "connectedness" of the strokes, which can have effects
e.g. in linejoins.

I'm somewhat concerned about the idea of mixing stroking instructions in
with path data because it muddles up geometry and painting styles.

In my mind, the best approach--in the sense of most generalizable--would be
to use the "superpath" idea, where you could construct a single filled
shape as the concatenation of multiple segments.  Fill styles would apply
to the entire shape, but stroke styles (including stroke: none) could apply
to subpaths.  (We'd probably be able to poach a lot of the CSS border style
rules for defining how to connect two stroke segments with different
styles.)

I confess I haven't had a chance to look through the various proposals for
superpath-type elements carefully, so I don't know if any of them currently
include the option of styling the strokes on subpaths individually.  But, I
don't expect that it would be a major conflict to try to integrate the
idea.  After all, since stroke styles are inherited, you would always be
able to stroke the entire superpath shape as normal just by setting the
stroke styles on it and not on the subpaths.

AmeliaBR