[Doc-SIG] using the same delimiter on the left and right..

[Edward D. Loper]

Tibs seems to have this strange notion that "real" markup
languages don't use the same characters for left and right
delimiters.. :) But almost any markup I can think of does...
'$' or '$$' in LaTeX for math mode..  '"' in XML/HTML for
attribute values.. etc.  I think that what makes delimiters
in ST seem like not-real-markup is that they are context-
dependant.  E.g., "'" in the middle of a word is different
from "'" at the beginning of a word.  So..  let's change
that.  Let's make all of our delimiters into real delimiters,
that can only be used for delimiting (or maybe also for
bullets, in the case of '*').  We could switch our "literal"
delimiter to "`".  So then we would have the following
reserved characters, that may not appear in text without
being quoted somehow:
    '<'    left delimiter for URLs
    '>'    right delmiter for URLs
    '#'    delimiter for inlines
    '`'    delimiter for literals
    '*'    delimiter for emph, maybe for strong.
    '::'   marker for literal regions

Then the only context-dependant characters that remain would
be start-list-item characters..  And if we wanted to, we could
use '* ' at the beginning of any list item, since it's 
reserved anyway... something like:

    * this is an unordered list item
    *1. this is an ordered list item

Well.. I'm not sure whether we'd want to do that or not.. We
may be happy with just using '1.' and assuming that no one will
start a line with a number that ends a sentence..  But I
think that reserving the delimiter characters might still be
a good idea..

Does this sound like a reasonable direction to go?  It
at least seems to me to be closer to a "real" markup language..

-Edward