Re: [office-comment] OpenFormula: Excel FLOOR Function

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

Dennis E. Hamilton:
> In fact, a translation from OpenFormula that substituted -CEILING(-x) for
> FLOOR(x) in going to OOXML (assuming there's really no FLOOR there) would
> commit the venial sin of not preserving a formula as written as closely as
> possible.  And of course, if that formula came back into OpenFormula, it is
> not OK to translate -CEILING(-x) to FLOOR(x), for the same reason.  
> 
> This did leave me wondering about the general problem of round-tripping in
> these cases, and how having formulas crammed into attribute values makes it
> hard to provide mark-up that has a round-trip-supporting preservation
> function (sort of like alternate renditions), along with a related problem,
> disambiguating user-defined functions.

I believe we currently _do_ have formula-preserving round-trip capabilities
in the general case.
We've been careful to include the function names for commonly-used functions.
If function F is _unique_ to foo.com's application, they can exchange it as:
 COM.FOO.F(...)
so it's still round-trip preserving.

We even have both "^" and "POWER", as well as the special postfix operator "%".

There are a few edge cases (e.g., we don't have a default but they do, so
the default will be "forced" into the loaded result if the use the function's
standard name).  But these should not cause any problem in the real world.

--- David A. Wheeler