On Nov 19, 2011, at 04:35 , Henrik Bengtsson wrote: > On Fri, Nov 18, 2011 at 9:34 AM, Kevin R. Coombes > <kevin.r.coom...@gmail.com> wrote: >> You can also see the odd behavior without wrapping round in another >> function: >> >>> round(100.1, digits=) >> [1] 100 > > Hmm... is there a reason for why the parser accepts that construct?
Yes. See e.g. help(alist) for actual usage. It can also be used to pass empty arguments to FUN in apply-constructs: a <- matrix(1:12, 3, 4) f <- function(i, j) a[i,j] lapply(1:4, f, i=) > Some example: > >> parse(text="f(a=)") > expression(f(a=)) > >> parse(text="f[a=]") > expression(f[a=]) > >> parse(text="(a=)") > Error in parse.default(text = "(a=)") : <text>:1:4: unexpected ')' > 1: (a=) > > /Henrik > >> >> On 11/18/2011 10:19 AM, Joris Meys wrote: >>> >>> On Fri, Nov 18, 2011 at 5:10 PM, Gavin Simpson<gavin.simp...@ucl.ac.uk> >>> wrote: >>>> >>>> round is indicated to not evaluate its arguments. I don't follow the C >>>> code well enough to know if it should be catching the missing argument >>>> further on - it must be because it is falling back to the default, but >>>> the above explains that the not evaluating arguments is intended. >>>> >>>> G >>> >>> So if I understand it right, the y argument is not evaluated in the >>> fun2 function but deeper in the C code. that explains the lack of the >>> error message, thanks! I keep on learning every day. >>> Cheers >>> >>> Joris >>> >> >> ______________________________________________ >> R-devel@r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-devel >> > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd....@cbs.dk Priv: pda...@gmail.com ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
