Thoughts on Issue #20

["Paul Prescod" <paul.prescod@blastradius.com>]

Apologies for not getting this out sooner. Better late than never.

#1. Is it important to have "include" and "passthrough" be distinct
values? Or can we merge their behaviour and say that include always
attempts to "passthrough" if the output format supports it.

#2. Is "printchar" really implementable in most output formats? E.g.
HTML, HTML Help? Is it easy or hard to implement in XSL-FO?

#3. What happens if two attributes on the same element suggest
conflicting colours? Or an inherited attribute suggests one colour and
an inner one suggests another.

#4. The logic for action is not intuitive because it is not the same as
in-document. In the document, we say that if an attribute is not
mentioned at all, that means "include". If it is mentioned with a
particular postive value, then it means "exclude everything except this
value". In the ditaval file, "include" is a no-op and "exclude" means
"exclude if this value is set." This is non-intuitive both because it is
inconsistent but also because it means that you end up listing
everything you DON'T want to handle. People are more comfortable with
positive logic than negative logic.

My proposal: include means "Include if this value (or another included
value) is in the list. Exclude otherwise."

In that model, "Exclude" would be the no-op.

 Paul Prescod