Orthoganlity Questions

Subject: Orthoganlity Questions
From: Paul Prescod <papresco@xxxxxxxxxxxxxxxxxxxxxxxxx>
Date: Fri Mar 28 23:52:20 1997 EST
Often the design decisions that we do not understand about a language
indicate the parts of that language that we fundamentally do not
understand. Other times they are "shortcuts" (for performance, backwards
compatibility, typing convenience, whatever). Occaisionally they are
just oversights. Here are a few things that are bothering me a little
about DSSSL:

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

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.

Why is there no (process-matching-descendants)? Sure, it is easy to
write. But still -- so is (process-children). I have to introduce the
concept of a node-list into my tutorial "early" just to implement this
one function. node-lists are important and useful, but there is an order
to learning things. This is probably not an oversight. So I probably
just don't understand the good reason it doesn't exist. Does anyone know
or want to guess?

 Paul Prescod

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