Formulas: "," and ";" as function parameter separators

["David A. Wheeler" <dwheeler@dwheeler.com>]

I'm trying to unify the various formula formats
(text:formula, text:condition, table:formula, draw:formula, and anim:formula)
into a single format. For the most part this is really
easy, they're _almost_ the same.

But I've immediately noticed one inconsistency: function parameter
separators.  Both draw:formula and anim:formula use comma (",") as
the separator.  On the other hand, OOo's table:formula
internally uses semicolon (";") as the function separator.
Semicolon has the advantage of working regardless of locale,
but comma is the more traditional parameter separator.

There are at least 3 options for unifying these:
* Change the OpenDocument specification to use ";"
   as function param separators everywhere (e.g., change
   draw:formula and anim:formula).
* Having the unified formula syntax accept both.
   This means nothing needs to be changed now in the spec.
   This also means that the text-as-displayed may be
   different in many locales from what's sent, which might
   be confusing and does add a burden to simple implementations.
   Consistency wouldn't be required in data, since both
   characters would work, and that might be a problem.
   This approach means that numbers MUST be
   sent using locale "C" (something that happens anyway,
   but that is an unfortunate side-effect).
* Require everyone use "," as the function parameter
   separator.  This would require changing OpenOffice's
   reading of spreadsheets, etc., to accept this.

Thoughts?  Anyone have a preference?
If this could be worked out, I think we end up
eliminating a bunch of different formula formats &
winnowing it down to one main one.
The notion of switching to ";" everywhere is appealing to
me, and if not that, switching to "," everywhere.

--- David A. Wheeler