> -----Original Message----- > From: r-devel-boun...@r-project.org > [mailto:r-devel-boun...@r-project.org] On Behalf Of Duncan Murdoch > Sent: Tuesday, February 10, 2009 7:12 AM > To: Stavros Macrakis > Cc: xinlee...@stat.math.ethz.ch; r-de...@stat.math.ethz.ch > Subject: Re: [Rd] Bug in subsetting data frame (PR#13515)
[ lots deleted ] > > Indeed! It is quite surprising that functions are defined > using ordinary > > assignment, but function lookup is different from normal variable > > evaluation, e.g. that after c<-4, c(10) is different from > (c)(10). Was this > > inspired by some other language? I don't think it's done > this way in any > > other language I can think of.... > I think originally there was no difference, and it caused the obvious > trouble when people used variable names like t and c other short > function names, so this was added. I don't remember whether the > different lookup rules showed up first in R or S. > > Duncan Murdoch Splus 3.4 (July 1996, based on SV3 dated "Apr 30 09:54:11 EDT 1992") distinguished function vs. non-function lookups. E.g., > f <- function(a,b,c) c(a,b,c) > f(11,12,13) [1] 11 12 13 Warning messages: looking for function "c", ignored local non-function in: f(11, 12, 13) I don't have easy access to any older version of S+. Somewhere along the line we dropped the warning. Bill Dunlap TIBCO Software Inc - Spotfire Division wdunlap tibco.com > ______________________________________________ > 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