>>>>> William Dunlap <wdun...@tibco.com>
>>>>> on Tue, 13 Oct 2015 09:12:34 -0700 writes:
> MM> but I don't think we'd want to
> MM> change all.equal.language() at this point in time
> Although it would be nice if all.equal looked at least at attributes of
> formulas
> so we did not get results like
> > form <- y ~ x1 %in% x2
> > all.equal(form, terms(form))
> [1] TRUE
> > all.equal(terms(y~x1+x2+Error(x3/x2), specials="Error"),
> terms(y~x1+x2+Error(x3/x2)))
> [1] TRUE
Hmm... of course, you have a very good point....
So, let me say
"Patches are welcome!"
(If
- they include changes to the *.Rd files [e.g., with an option
to remain back-bug-compatible]
- are well tested, e.g., run 'make check-all' )
[Yes, I think I know why they probably won't come from you,
Bill, unfortunately ..]
Martin
> Bill Dunlap
> TIBCO Software
> wdunlap tibco.com
> On Tue, Oct 13, 2015 at 8:39 AM, Martin Maechler <maech...@stat.math.ethz.ch
> > wrote:
> > >>>>> Duncan Murdoch <murdoch.dun...@gmail.com>
> > >>>>> on Mon, 12 Oct 2015 19:31:11 -0400 writes:
> >
> > > On 12/10/2015 9:51 AM, Ben Bolker wrote:
> > >> Duncan Murdoch <murdoch.duncan <at> gmail.com> writes:
> > >>
> > BB>
> > >>>>> It seems odd/inconvenient to me that the
> > >>>>> "ignore.environment" argument of identical() only
> > >>>>> applies to closures (which I read as 'functions' --
> > >>>>> someone can enlighten me about the technical
> > >>>>> differences between functions and closures if they
> > >>>>> like -- see below for consequences of my confusion).
> > >>>>> This is certainly not a bug, it's clearly documented,
> > >>>>> but it seems like a design flaw. It would certainly
> > >>>>> be convenient to be able to ignore differences in
> > >>>>> environments when comparing complex objects with lots
> > >>>>> of deeply nested formula and terms objects with
> > >>>>> environments ...
> > >>>>>
> > >>>>> Can anyone suggest a reason for this design?
> > >>>>>
> > >>
> > >> [snip]
> > >>
> > >>>>> Actually, maybe I don't understand how this is
> > >>>>> supposed to work since I thought this would be TRUE:
> > >>>>>
> > >>>>> f1 <- function() {}
> > >>>>> f2 <- function() {}
> > >>>>> environment(f1) <- new.env()
> > >>>>> environment(f2) <- new.env()
> > >>>>> identical(f1,f2,ignore.environment=TRUE) ## FALSE
> > >>>>
> > >>>> Those two functions likely have different srcref
> > >>>> attributes. If you created f2 using f2 <- f1, you'd
> > >>>> get your expected result.
> > >>>>
> > >>
> > >> [snip]
> > >>
> > >> Thanks for the clarification about closures
> > >> vs. functions.
> > >>
> > >> [snip]
> > >>
> > >> You're right that the srcref attributes are different;
> > >> although their bodies are the same, they have their own
> > >> environments that differ. For me, this makes the
> > >> intended use of ignore.environment= even more puzzling;
> > >> given that environments are not ignored recursively
> > >> (that's not exactly what I mean -- I mean ignoring all
> > >> environments of components of an object), I have trouble
> > >> understanding the use case for ignore.environnment ...
> > >> maybe it was developed before srcrefs existed?
> >
> > > I think it simply means "ignore.environment.of.closures",
> > > as the description says, but that's too long to be a
> > > convenient arg name.
> >
> > > Closures have three parts: the formals, the body and the
> > > environment. (Actually, 4 parts: like almost all R
> > > objects, they may also have attributes.)
> >
> > > That arg just says to ignore the environment part when
> > > comparing closures. It doesn't say to ignore environments
> > > in general.
> >
> > For another beat on a dead horse, @ Ben:
> >
> > You could either use options(keep.source = FALSE) in your
> > enviroment such that your functions should not have any 'srcref'
> > attributes anymore,
> >
> > or probably more sensible, use
> >
> > all.equal(f1, f2) rather than identical(f1, f2, ..)
> >
> > which I think should really do what you want
> > [even though it ends up using string comparison after deparse(.)
> > .. about which one can debate... but I don't think we'd want to
> > change all.equal.language() at this point in time].
> >
> > Martin
> >
> >
> > >>
> > >> In the R code base it's used in checkConflicts (to see if
> > >> a function is re-exported) and in getAnywhere ...
> > >>
> >
> > > I'd say those uses are slightly bogus. You should
> > > generally remember that closures have 3 (or 4) parts, and
> > > not go around comparing only two (or 3) of them.
> >
> > > Duncan Murdoch
> >
> > > ______________________________________________
> > > 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
> >
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
