[Rd] bindingIsLocked returns illogical logical
Prof Brian Ripley
ripley at stats.ox.ac.uk
Mon May 15 09:05:32 CEST 2006
On Sun, 14 May 2006, Seth Falcon wrote:
> Martin Morgan <mtmorgan at fhcrc.org> writes:
>> bindingIsLocked applied to a locked binding returns a 'logical' that
>> is niether true nor false.
> Is this a philosophical question? :-)
But there is such a value defined for R logical vectors.
> Here's what I think is going on:
> BINDING_IS_LOCKED does not return 0/1, but the result of a bit op that
> will be either 0 or some int where bit 14 is set.
> The behavior you describe is consistent with a logical value escaping
> to R where the underlying int is some x > 1.
> I wonder if ScalarLogical should force 0/1:
Not a good idea: what about the third value, NA?
> Index: include/Rinlinedfuns.h
> --- include/Rinlinedfuns.h (revision 38060)
> +++ include/Rinlinedfuns.h (working copy)
> @@ -494,7 +494,7 @@
> INLINE_FUN SEXP ScalarLogical(int x)
> SEXP ans = allocVector(LGLSXP, 1);
> - INTEGER(ans) = x;
> + INTEGER(ans) = (x == 0) ? 0 : 1;
> return ans;
> Otherwise, I think do_bndIsLocked needs to make a similar operation
> before calling ScalarLogical. But preventing these all purpose
> logicals from escaping would seem to be a good argument for changing
I think it needs to handle NAs.
Brian D. Ripley, ripley at stats.ox.ac.uk
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
More information about the R-devel