Re: [office-comment] OpenFormula (OpenOFormula?)- I'm working ona draft.

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

Gary Edwards wrote:
> Hi David,
> 
> Thanks for the concerned comments and all the considerable effort you 
> have put into solving this problem.  You're challenging us all to go 
> where none have dared tread before.  So go ahead and lead the way.
...
> Your kindness in the way you're approaching this issue is much 
> appreciated, and i personally like your proposal for a separate 
> standalone "OpenFormula" specification.  It may be a good way to break 
> through the logistics of the current specification situation, while 
> allowing room for the continued push to develop a truly universal file 
> format that covers the ever evolving needs of a rapidly expanding 
> productivity environment.

Great!  I'm glad you like my proposal for a separate document.
It sounds to me like that would be the best way to move forward.
That way, working on a lengthier specifications for formulas
won't hold up progress on the whole Open Document specification.
Especially since formula specification is a clearly separable area.

I'm currently working through to create a first draft
of this stand-alone document, and hope to post a first draft
in a few days.  I'll base it on the docs I posted before.

Here are my current thoughts... I'd REALLY appreciate any
comments about them:
* I'd like to unify all the different places formulas appear,
   e.g., tables/spreadsheets, text:formula, draw, animation.
   Having a single consistent formula syntax would help the
   user experience, and it's easier to implement too.
* To do that, I think I need to define something I'll call
   "context", which is the environment given to the formula.
   If a formula has a bare variable such as in
   "=mystuff+3", there needs to be a way to find "mystuff".
   The answer: the formula looks for that in the current
   "context".  So this means that draw'ing would have
   a different context than text (text would have a context
   that included page number values, etc.).  In a spreadsheet,
   bare variables include named ranges. The context
   also identifies the current table; if there's
   no current table, then any reference to the current
   table will fail.
* To do that, I also MUST include definitions for the
   functions required in the specification for draw:formula
   such as sin(), cos(), etc.  Eventually a large number
   of predefined functions need to be defined, though not
   necessarily in this specification.. there might even be
   another supplemental document defining more functions.
* Some formulas use "<>" (like spreadsheets),
   some use "!=" (like draw:).  The simplest solution is to
   require all readers to read both; then it just doesn't matter,
   and I don't see a problem with accepting both.
   OOo currently uses <> in spreadsheets, but "!=" has the
   advantage of being easier to read in the XML
   because "!=" doesn't require any character escapes.
* If formulas begin with a letter, then the following letters
   must be followed by a colon and that gives the namespace
   for that formula.  If the formula begins with "=", then
   the formula is provided in a special default namespace
   usually given the prefix "formula:" (which you can also
   specifically provide)... and the following text must
   meet the OpenFormula specification.


>  I'm even wondering if this isn't something 
> that should be tossed back to the OOo Community as a project?

I've never seen a "community" create a first draft of any
doc or program.  Usually someone with an itch creates the first draft.
If others think it shows promise, they then work to improve it.
Hopefully, I can create something that'd work as a starting point.

 > One of
> the great attributes of the OASIS OpenDocument TC is that we have armies 
> of engineers and beta testers from OOo, StarOffice, and KOffice waiting 
> to rip into the next insolvable problem, and do what has never been done 
> before :)

I think the OASIS OpenDocument TC is the right
place for this OpenFormula specification.  I view it as basically
a supplemental document, one that will require discussion among
OOo, StarOffice, KOffice, and others.... and one that might even
follow this process through to an OASIS vote and ISO
(as an independent document or as an appendix).

--- David A. Wheeler