On Aug 10, 2014, at 10:07 PM, Winston Chang <winstoncha...@gmail.com> wrote:
> Another oddity - even though there's an error thrown in assignment to > x$y$z, the assignment succeeds. > > x <- new.env() > x$y <- new.env() > lockEnvironment(x, bindings = TRUE) > x$y$z <- 1 > # Error in x$y$z <- 1 : cannot change value of locked binding for 'y' > > x$y$z > # [1] 1 > > > So I assume there must be a bug somewhere in here. > Why? In both cases (including your previous post) the you have two separate assignments: (x$y)$z <-1 followed by x$y <- y. So the first one always succeeds since there is no reason for it not to, but the second one doesn't because the binding is locked. I presume the confusion comes from the fact that environments are mutable, so x$y changes even if it was not assigned so it's irrelevant if the second assignment succeeds or not. Cheers, Simon > -Winston > > > > On Sun, Aug 10, 2014 at 8:46 PM, Winston Chang <winstoncha...@gmail.com> > wrote: > >> If an environment x contains a locked binding y which is also an >> environment, and then you try to assign a value to a binding inside of >> y, it can either succeed or fail, depending on how you refer to >> environment y. >> >> x <- new.env() >> x$y <- new.env() >> lockEnvironment(x, bindings = TRUE) >> >> # This assignment fails >> x$y$z <- 1 >> # Error in x$y$z <- 1 : cannot change value of locked binding for 'y' >> >> # Saving x$y to another variable, and then assigning there works >> y2 <- x$y >> y2$z <- 10 # OK >> print(x$y$z) >> # 10 >> >> >> Is this a bug or a feature? I realize that x$y is a locked binding >> while y2 is not. >> >> -Winston >> > > [[alternative HTML version deleted]] > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel > ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
