David A. Wheeler scripsit:

> A parsing directive is <i>valid</i> if and only if it begins
> at the beginning of a line, it is terminated by an end of line,
> and it is not contained inside an expression
> (e.g., inside parentheses or a collecting list).

I'd simply say that it is an error unless a parsing directive begins,
etc., and drop the word "valid".

> An implementation may be a "native implementation".
> A native implementation <em>MUST</em> also accept,
> in its standard datum readers,
> a valid <code>#!sweet</code> directive,
> and from then on it <em>MUST</em> accept
> sweet-expressions from the same port
> (until some conflicting directive or instruction is given).

"Also" is a little vague.  I'd say "In addition to all other
requirements, a native implementation MUST etc."

> A <i>well-formatted</i> s-expression is an expression interpreted
> identically by both traditional s-expressions and by sweet-expressions.

I'm not a fan of this term.  What about "polyglot" instead?  (A document
which is both valid HTML and well-formed XML and has the same meaning
in both interpretations is called "polyglot HTML".)

--
John Cowan      http://www.ccil.org/~cowan      xxxxxx@ccil.org
Be yourself.  Especially do not feign a working knowledge of RDF where
no such knowledge exists.  Neither be cynical about RELAX NG; for in
the face of all aridity and disenchantment in the world of markup,
James Clark is as perennial as the grass.  --DeXiderata, Sean McGrath