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Re: Orthoganlity Questions

From: James Clark <>
Date: Sat, 29 Mar 1997 15:27:24 +0700
At 23:54 28/03/97 -0500, Paul Prescod wrote:

>Why can't element construction rules be at least as powerful as
>match-element? and process-matching-children? Guess: implementation

So that when an element matches two different element construction rules,
it's always obvious which is the more specific.

>Why is there no "or" or "not" for match-element? There is a very
>coarse-grained "or" where you can duplicate an entire pattern, but not
>within patterns. Guess: implementation simplicity.

To keep the syntax for patterns really simple for the user.

>Why is there no (process-matching-descendants)? Sure, it is easy to
>write. But still -- so is (process-children).

Use of process-matching-descendants is prone to error: if you do
(process-matching-descendants 'div) and a div element has a child div
element, and the rule for the div element doesn't do anything special, then
the child div element will get processed twice.
process-matching-descendants doesn't seem to me to provide anything that you
can't do better with modes and process-children.