Hi all,
Here my view:
We should not change the current behavior, because
- It is one of three allowed result, so it is not an error.
- Changing it, would break old documents.
- returning 1 will be consistent with SERIESSUM (I know, that SERIESSUM
is currently not yet adapted to ODF1.2, but for SERIESSUM there is no
choice.)
- returning 1 is the same as in BASIC.
Andrea Pescetti schrieb:
A good practical example of backwards-incompatible changes in version
4.0 is the behavior of Calc while computing 0 ^ 0.
You can find a long issue, with different points of view, about this at:
https://issues.apache.org/ooo/show_bug.cgi?id=114430
but in short:
- Obviously, 0 ^ 0 is an illegal operation in mathematics and the result
is undefined/invalid
- In 3.4.1, "=0 ^ 0" returns 1
- In 4.0, as patched by Pedro (see issue), "=0 ^ 0" would return an error
- According to ODF, valid results are 0, 1, error
- We gain interoperability since Excel returns an error too
- We lose backwards compatibility if someone was relying on the fact
that OpenOffice returns 1 as the result of "=0 ^ 0"
I'm OK with the proposed change, provided we advertise it in the release
notes. I'm not aware of any cases where someone is actively using the
fact that in Calc 0 ^ 0 evaluates to 1, and even if someone did, I would
say that his spreadsheets should not compute 0 ^ 0 at all.
It allows you to design a generic table of value in some cases, without
the need to use always case distinction.
A side
benefit would be that school students quickly wanting to find out what
is the result of 0 ^ 0 would be told the truth (it's an error) instead
of being presented with a numeric result and no warnings. (Then the
student would go on and write "= - 2 ^ 2" and have a lot of fun, but
this is out of scope here).
The question is, whether "0^0=1" is more useful than "0^0=undefined".
Is there consensus that this is a reasonable backwards-incompatible
change, or compelling reasons to revert it?
There is no consensus.
Kind regards
Regina
