Recap syntax ideas for Markdown?

[A. Pagaltzis]

* Matthias Steffens <mat at extracts.de> [1970-01-01 01:00]:
> Sorry to repeat myself, but for everyone who wants to use
> markdown to markup scientific or bibliographic texts, the lack
> of subscript and superscript in markdown is a real showstopper.
> 
> There are a lot of scientific disciplines that don't need fancy
> math formatting and where italic, super/subscript and greek
> letters is all that's needed.

+1 on all counts.

I like the ^ and ^^ syntax that’s been suggested elsewhere
insofar as it’s the first thing that came to mind for me before
seeing it, which speaks to its intuitiveness.

However, I think a better proposal might be ^_ as the subscript
marker and another _ as the closing delimiter. That rendering
invokes more of an association with the intended effect: `H^_2_O`
as opposed to `H^^2^O`. If you actually want an emphasized
superscript, just put a space in there: `x^ _y_^` – this should
be special cased to drop that space.

In terms of implementation this should be fairly unambiguous to
interpret with a stateful parser, though a search&replace combine
harvester like Markdown.pl’s current implementation will probably
be difficult to get right with respect to all the corner cases
involving emphasis.

(On a vaguely related tangent, I still think Markdown would have
been better off to not waste underscores on emphasis. Asterisks
work well enough for that purpose, and underscores could have
been put to use for other syntax. I also think it is **hugely**
fortunate that slashes are not interpreted as italics or
emphasis, since that would have made Markdown much less useful to
many a /usr/bin/geek...)

Regards,
-- 
Aristotle