Re: [office-formula] Urgent: external named expressions

[Eike Rathke <erack@sun.com>]

Hi,

On Friday, 2008-11-21 16:42:11 -0500, David A. Wheeler wrote:

> Eike:
> > I think that it would be much better to treat external and sheet-local
> > named expressions similar to references by enclosing them in a pair of
> > square brackets. For one, they _are_ references, as they refer to
> > another sheet or document. Second, it would be easier to parse as the
> > square brackets clearly delimit the expression, and it may even fit into
> > already existing reference parsers.
> 
> I have no objection in principle.  As you note, they ARE references,
> so it's quite arguable that it's cleaner to do so.
> 
> An LL(1) grammar will have to be careful, since after [
> and a single quoted identifier they'll have to look at the next non-whitespace
> to figure out what it is (# or .).  But that's quite doable while staying
> LL(1), and you have to do that with the current grammar too.

The definition of references does include optional external source
locators, so after a single quoted identifier may actually follow
already a # if it was a document URL, and a . if it was a sheet name.
New is that these two may be followed by $$.

Btw, the example
='./openformula-testsuite.ods'#'$$FOUR
is wrong and has an extraneous single quote, correct would be
='./openformula-testsuite.ods'#$$FOUR
with the new syntax changing it to
=['./openformula-testsuite.ods'#$$FOUR]

I'll correct that on the fly.

> I would suggest a note to implementations that they should consider
> implementing the older format (without [...]) so that they can read old
> versions, until the transition is complete.

Would be good to know if any implementation in public already writes the
old definition. If not, things would be much easier. Calc doesn't. What
about Gnumeric, KSpread and some Excel-plugin? Others?

  Eike

-- 
Automatic string conversions considered dangerous. They are the GOTO statements
of spreadsheets.  --Robert Weir on the OpenDocument formula subcommittee's list.

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