# What is "..." when it's empty? -- differences to S

**Martin Maechler
**
Martin Maechler <maechler@stat.math.ethz.ch>

*Sat, 26 Jun 1999 14:23:32 +0200*

i) (function(x, ...) length(...))(1)
gives 0 in S (plus 3.4) and an error in R.
It also gives an error in Splus 5.0r3.
So we could well remain as we are... however
ii) (function(x, ...) length(...))(1,2)
gives 1 in all dialects of S that I have available.
So by my `continuation logic', I'd argue that "i)" above should give 0
(and R and S-plus 5.0r3 behave inconsistently.
Do we yet have any documentation on "..." ??
In both Splus 3.4 and 5.0r3,
(function(x, ...) mode(...))(1) returns "missing"
whereas R gives an interesting error:
R> trace(mode)
R> (function(x, ...) mode(...))(1)
trace: mode(...)
Error: Argument "x" is missing, with no default
---
What is desired for R?
BTW: Found the above problem when trying to use
C(<factor>) without a 2nd argument; a patch for that will be in the
snapshots..
Martin Maechler <maechler@stat.math.ethz.ch> http://stat.ethz.ch/~maechler/
Seminar fuer Statistik, ETH-Zentrum SOL G1; Sonneggstr.33
ETH (Federal Inst. Technology) 8092 Zurich SWITZERLAND
phone: x-41-1-632-3408 fax: ...-1086 <><
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !) To: r-devel-request@stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._