In general, should we expect that the ability to compute on the language within R will decrease over time? Otherwise, I presume if you do change the behaviour of missing then you'll still provide some way to create/call functions with missing arguments.
Hadley On Mon, Feb 18, 2013 at 12:31 PM, <luke-tier...@uiowa.edu> wrote: > I wouldn't count on any way of capturing this thing being reliable in > the long term. As I recall what I do in codetools and the compiler is > use features of missing() to test for it, but try to abstract those > uses into one or two places only so I can easily change them if > missing()'s behavior changes. Basically this internal thing > _shouldn't_ be visible at R level, and if we ever figure out how to > make that happen it will. > > Best, > > luke > > > On Mon, 18 Feb 2013, Hadley Wickham wrote: > >> Hi all, >> >> I think there's a small buglet in quote: >> >> str(quote()) >> # Error in quote() : 0 arguments passed to 'quote' which requires 1 >> str(quote(expr = )) >> # symbol >> >> I bring this up because this seems like the most natural way of >> capturing the "missing" symbol with pure R code, compared to >> substitute() or bquote() or formals(plot)$x >> >> Hadley >> >> > > -- > Luke Tierney > Chair, Statistics and Actuarial Science > Ralph E. Wareham Professor of Mathematical Sciences > University of Iowa Phone: 319-335-3386 > Department of Statistics and Fax: 319-335-3017 > Actuarial Science > 241 Schaeffer Hall email: luke-tier...@uiowa.edu > Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu -- Chief Scientist, RStudio http://had.co.nz/ ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
