Recap syntax ideas for Markdown?

[Damian Cugley]

On 4/7/05, John Gruber <gruber at fedora.net> wrote:
> David Engel <engel5 at engel5.net> wrote on 04/06/05 at 12:21pm:

> > 1. Subsript/superscript -- Superscript seems to be acceptable
> > (and easy?) with `word^superscript^`. People have asked about
> > using a space to close it, i.e., `x^2 `, but that raised
> > questions about properly designating superscripts with spaces,
> > where enclosing is clearer, i.e., `x^2 + 4^`. 

I'm new here so this may already have been discussed, but I would
prefer that x^2 was represented `x^2`.   It would supify a single
token (word or number).  For anything other than a single token, we
could allow `x^(a + b)`.  In other words, two superscriptificiation
punctuations, `^` for the simple case and `^(...)` for the compex
case.  I think this would be reasonably implementable, and also looks
very natural in the text.

Pity the underscore is unavailable for subscripts. I could imagine
some rule where interior underscores are treated differently from
bracketing underscores (e.g., `_x_` versus `x_3`), but the
implementation would get fiddly.  If backward compatibility were not
an issue, I'd change the rules to use only `*...*` for emphasis,
leaving `_` for subscripts.

If we're going to contemplate using Unicode, there's always the
arrows, as in x↓SUB↑SUP. (Arrows U+2191 and U+2193 via Character
Palette or Character Map.)  Depends on Unicode-savvy editors and mail
programs, though.

Has there been any discussion of integrating Markdown with the `$...$`
conventions of [Itex][1]? Then `$x_3$` in unambiguously a short 
mathematical formula. In fact the easiest implementation would be to
run the Itex filter first, leaving HTML or MATHML mark-up that
Makrdown would pass verbatim. Or Markdown could have an option to
interpret an HTML-compatible subset  (thus not generating MATHML).
Apologies if these ideas have already been mooted.... :-)


  [1]: http://pear.math.pitt.edu/mathzilla/itex2mmlItex.html
-- 
Damian Cugley, Alleged Literature
http://www.alleged.org.uk/pdc/