On 12 Aug 2014, at 08:29 , Simon Knapp <sleepingw...@gmail.com> wrote:
> Hi List, > > Is it possible to define how 'in' works for an object of a specific class > (to achieve a similar result to implementing the iterator protocol in a > class Python)? > No, because 'in' doesn't really exist, it is "syntactic sugar" to sweeten a call to the "for" function with its three arguments. E.g. > `for`(i,1:2,print(i)) [1] 1 [1] 2 So what you're really asking for is something like a `for` with class dispatch or the two first arguments replaced by an iterator mechanism. That's not in the cards, at least at the moment, but I suppose it isn't completely out of the question either -- ideas of this sort get bandied around occasionally. It would require changes to R's internals; it is not something you can do in (say) a package. > Cheers, > Simon Knapp > > [[alternative HTML version deleted]] > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd....@cbs.dk Priv: pda...@gmail.com ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
