Note that this still has the restriction that getdots must be used directly in the function which is to be deparsed so one could not, for example, put it in another utility function which deparses the function and extracts the first component. To do that you need to pass the frame:
f <- function(n = sys.parent()) match.call(sys.function(n), call=sys.call(n)) # test - note that g calls first which calls f so f is not directly called by g first <- function(n = sys.parent()) f(n)[1:2] g <- function(x,...) first() g(x,a,b,c) g(x = x, a, b, c) On 3/2/06, Matthew Dowle <[EMAIL PROTECTED]> wrote: > > That works well. So the final version is: > getdots = function() as.character(match.call(sys.function(-1), > call=sys.call(-1), expand.dots=FALSE)$...) > > Thank you both for your help. > > > -----Original Message----- > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > > Behalf Of Peter Dalgaard > > Sent: 02 March 2006 18:07 > > To: Matthew Dowle > > Cc: 'Prof Brian Ripley'; '[email protected]' > > Subject: Re: [R] Deparsing '...' > > > > > > Matthew Dowle <[EMAIL PROTECTED]> writes: > > > > > That's even neater. But when its called from within > > another function, > > > this happens, see below. I was planning to call f something like > > > 'getdots' and use it in several functions that need to do this. > > > > > > > f <- function(...) as.character(match.call())[-1] > > > > f(a,b,c) > > > [1] "a" "b" "c" > > > > g = function(x,...) f(...) > > > > g(x,a,b,c) > > > [1] "..1" "..2" "..3" > > > > Yes, that will (and must) happen. If you really want to go > > that route, you need something in the veins of > > > > > f <- function() match.call(sys.function(-1), call=sys.call(-1)) g = > > > function(x,...) f() > > > g(x,a,b,c) > > g(x = x, a, b, c) > > > > > > > > > -----Original Message----- > > > > From: Prof Brian Ripley [mailto:[EMAIL PROTECTED] > > > > Sent: 02 March 2006 17:18 > > > > To: Matthew Dowle > > > > Cc: '[email protected]' > > > > Subject: Re: [R] Deparsing '...' > > > > > > > > > > > > f <- function(...) as.character(match.call())[-1] > > > > > f(x,a,b,c*d) > > > > [1] "x" "a" "b" "c * d" > > > > > > > > On Thu, 2 Mar 2006, Matthew Dowle wrote: > > > > > > > > > > > > > > Hi, > > > > > > > > > > The following function works, but is there a neater way > > to write > > > > > it? > > > > > > > > > > f = function(x,...) > > > > > { > > > > > # return a character vector of the arguments passed > > in after 'x' > > > > > gsub(" > > > > > > > ","",unlist(strsplit(deparse(substitute(list(...))),"[(,)]")))[-1] > > > > > } > > > > > > > > > >> f(x,a,b,c*d) > > > > > [1] "a" "b" "c*d" > > > > >> > > > > > > > > > > Thanks. > > > > > > > > -- > > > > Brian D. Ripley, [EMAIL PROTECTED] > > > > Professor of Applied Statistics, > > http://www.stats.ox.ac.uk/~ripley/ > > > > University of Oxford, Tel: +44 1865 272861 (self) > > > > 1 South Parks Road, +44 1865 272866 (PA) > > > > Oxford OX1 3TG, UK Fax: +44 1865 272595 > > > > > > > > > > ______________________________________________ > > > [email protected] mailing list > > > https://stat.ethz.ch/mailman/listinfo/r-help > > > PLEASE do read the posting guide! > > > http://www.R-project.org/posting-guide.html > > > > > > > -- > > O__ ---- Peter Dalgaard Øster Farimagsgade 5, Entr.B > > c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K > > (*) \(*) -- University of Copenhagen Denmark Ph: > > (+45) 35327918 > > ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: > > (+45) 35327907 > > > > > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
