Hello Sapan,
Most of the function implementations present already were added before
version 3.1. Since then there have been about a dozen implementations
added. This usually happens when someone notices a function missing that
they need. There is pretty good coverage of the most commonly used
functions (judging from the lack of requests in bugzilla). However there
are at least 150 built-in functions and another 90 odd "Analysis ToolPak"
functions still to be done. Some of these sound like they might be commonly
required (e.g. COUNTBLANK, DATEDIFF, IRR) but it's hard to tell which are
worth spending time on. The POI project is always happy to receive code
contributions even if it is just for unimplemented functions.
As a follow-on from my comment above ("Perhaps an exception should have been
thrown instead of silently setting an invalid error code."), I have made a
change to that effect:
http://svn.apache.org/viewvc?view=rev&revision=736505
>From POI 3.5 onwards, if you evaluate a function that is not implemented
yet, a public unchecked exception (NotImplementedException) will be thrown.
regards,
Josh
