crash bug in get("function.name")() (PR#1211)
I don't think I'll get to look at this cerefully today, but here is just a thought: My recollection is that NextMethod needs to be called only from within a usemethod dispatch because the dispatch needs to set up stuff in the environment that NextMethod needs. If you do print.a <- function(...) NextMethod() and then call print.a directly then the stuff NextMethod needs isn't set up, so NextMethod can't do anything useful. I think the do_nextmethod tries to detect this and raise an error, but for some reason it isn't detecting the problem here. luke
On Wed, Dec 12, 2001 at 02:11:07PM +0100, Peter Dalgaard BSA wrote:
Rich Heiberger <rmh@surfer.sbm.temple.edu> writes:
Peter, your explanation looks right to me, and is certainly consistent
with the crash behavior of
get("print.a")
The R-1.4.0 error message is a good check.
I would think the explanation should prevent the other example from
working as well. But this one works
get("print.factor")(tmp)
exactly as expected.
Both of these examples work correctly in S-Plus 4.5
(S-PLUS 3.4 too)
There's no NextMethod in print.factor, but I was wrong on the other
example: It has NextMethod("print",....) with an explicit generic, so
I don't think it should go near the CAR(call) bit at all.
I'll take a closer look, but there's also a few other nasty bugs
nagging us at the moment, and this looks like it could require surgery
to do_nextmethod with some risk of complications.
--
O__ ---- Peter Dalgaard Blegdamsvej 3
c/ /'_ --- Dept. of Biostatistics 2200 Cph. N
(*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard@biostat.ku.dk) FAX: (+45) 35327907
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Luke Tierney University of Minnesota Phone: 612-625-7843 School of Statistics Fax: 612-624-8868 313 Ford Hall, 224 Church St. S.E. email: luke@stat.umn.edu Minneapolis, MN 55455 USA WWW: http://www.stat.umn.edu -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-devel-request@stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._