I mentioned in my original post that Sweave()/knit()/... can be considered as the "new" source(). They can do the same thing as source() does. I agree that fully evaluating the code is valuable, but it is not a problem since the weave functions do fully evaluate the code. If there is a reason for why source() an R script is preferred, I guess it is users' familiarity with .R instead of .Rnw/.Rmd/..., however, I guess it would be painful to read the pure R script tangled from the source document without the original narratives.
So what do we really lose if we turn off tangle? We lose an R script as a derivative from the source document, but we do not lose the code evaluation. Regards, Yihui -- Yihui Xie <xieyi...@gmail.com> Web: http://yihui.name On Sat, May 31, 2014 at 6:20 PM, Martin Morgan <mtmor...@fhcrc.org> wrote: > On 05/31/2014 03:52 PM, Yihui Xie wrote: >> >> Note the test has been done once in weave, since R CMD check will try >> to rebuild vignettes. The problem is whether the related tools in R >> should change their tangle utilities so we can **repeat** the test, >> and it seems the answer is "no" in my eyes. >> >> Regards, >> Yihui >> -- >> Yihui Xie <xieyi...@gmail.com> >> Web: http://yihui.name >> >> >> On Sat, May 31, 2014 at 4:54 PM, Gabriel Becker <gmbec...@ucdavis.edu> >> wrote: >>> >>> >>> >>> >>> On Fri, May 30, 2014 at 9:22 PM, Yihui Xie <x...@yihui.name> wrote: >>>> >>>> >>>> Hi Kevin, >>>> >>>> >>>> I tend to adopt Henrik's idea, i.e., to provide vignette >>>> engines that just ignore tangle. At the moment, it seems R CMD check > > > It is very useful, pedagogically and when reproducing analyses, to be able > to source() the tangled .R code into an R session, analogous to running > example code with example(). The documentation for ?Stangle does read > > (Code inside '\Sexpr{}' statements is ignored by 'Stangle'.) > > So my 'vote' (recognizing that I don't have one of those) is to incorporate > \Sexpr{} expressions into the tangled code, or to continue to flag use of > Sexpr with side effects as errors (indirectly, by source()ing the tangled > code), rather than writing engines that ignore tangle. > > It is very valuable to all parties to write a vignette with code that is > fully evaluated; otherwise, it is too easy for bit rot to seep in, or to > 'fake' it in a way that seems innocent but is misleading. > > Martin Morgan ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
