Message-ID: <96f3f5b1-71a1-f7d2-c291-df890a2fb493@gmail.com>
Date: 2020-12-01T16:08:25Z
From: Duncan Murdoch
Subject: all.equal applied to function closures
In-Reply-To: <CAHqSRuQ0mrNnExHvpMhMow99ZqoAFkYLE3Pg-SZBxipokJS=2g@mail.gmail.com>
One more comment: it might be worthwhile reporting on a case where
identical(e1, e2) fails when those are the environments associated with
two functions (though I think not by default in all.equal.environment).
Functions can modify variables in their environment, so examples like
the open.account example in the R-intro manual would distinguish between
ross and robert even if the balances matched.
Duncan Murdoch
On 01/12/2020 10:37 a.m., Bill Dunlap wrote:
> Probably all.equal.environment's do1() could be enhanced to do the
> recursion (and look at the environments' attributes).? I wrote a
> separate function because it was easier to experiment that way (e.g.,
> when to stop recursing?- it stops when one environment is a top-level
> environment or the empty environment).? I've been thinking about similar
> recursion options for ls.str() - it would make it easier to debug
> refClass and R6 code where the data is somewhere in a stack of environments.
>
> > E1 <- list2env(list(X=1.1, Y=1.2), parent=list2env(list(p=1.3),
> parent=baseenv()))
> > E2 <- list2env(list(X=1.1, Y=1.2), parent=list2env(list(p=1.4),
> parent=baseenv()))
> > base::all.equal.environment(E1,E2)
> [1] TRUE
> > globalenv()$all.equal.environment(E1,E2)
> [1] "<parent.env> Component ?p?: Mean relative difference: 0.07692308"
> >
> > E3 <- list2env(list(X=1.1, Y=1.2), parent=list2env(list(p=1.5),
> parent=new.env(parent=baseenv())))
> > base::all.equal.environment(E1,E3)
> [1] TRUE
> > globalenv()$all.equal.environment(E1,E3)
> [1] "<parent.env> Component ?p?: Mean relative difference: 0.1538462"
> [2] "<parent.env> <parent.env> target is <environment: base> and current
> is <environment: 0x564e806705c8>"
>
> On Tue, Dec 1, 2020 at 1:31 AM Martin Maechler
> <maechler at stat.math.ethz.ch <mailto:maechler at stat.math.ethz.ch>> wrote:
>
> >>>>> Bill Dunlap
> >>>>>? ? ?on Mon, 30 Nov 2020 13:41:54 -0800 writes:
>
> ? ? > To make the comparison more complete, all.equal.environment
> could compare
> ? ? > the parents of the target and current environments.? That
> would have to be
> ? ? > recursive but could stop at the first 'top level environment'
> (the global,
> ? ? > empty, or a package-related environment generally) and use
> identical
> ? ? > there.? E.g.,
>
> ? ? > > f1 <- function(x) (function(){ expx <- exp(x) ; function(y)
> y + expx})()
> ? ? > > all.equal(f1(2), f1(3))
> ? ? > [1] "Environments: Component ?expx?: Mean relative
> difference: 1.718282"
> ? ? >
> ? ? > [2] "Environments: <parent.env> Component ?x?: Mean relative
> difference:
> ? ? > 0.5"
>
> ? ? > This is from the following, where I avoided putting the existing
> ? ? > non-recursive all.equal.environment into the body of this one.
>
> ? ? > all.equal.environment <-
> ? ? > function(target, current, ...)
> ? ? > {
> ? ? >? ? ?.all.equal.environment <- base::all.equal.environment #
> temporary hack
> ? ? >? ? ?stopifnot(is.environment(target), is.environment(current))
> ? ? >? ? ?if (identical(target, current)) {
> ? ? >? ? ? ? ?TRUE
> ? ? >? ? ?} else {
> ? ? >? ? ? ? ?msg <- NULL # TODO: check attributes
> ? ? >? ? ? ? ?# deal with emptyenv now since parent.env(emptyenv())
> gives error
> ? ? >? ? ? ? ?# and topenv(emptyenv()) gives GlobalEnv
> ? ? >? ? ? ? ?eTarget <- identical(target, emptyenv()) ||
> ? ? > identical(target,topenv(target))
> ? ? >? ? ? ? ?eCurrent <- identical(current, emptyenv()) ||
> ? ? > identical(current,topenv(current))
> ? ? >? ? ? ? ?if (eTarget || eCurrent) {
> ? ? >? ? ? ? ? ? ?msg <- c(msg, paste("target is", format(target),
> "and current
> ? ? > is", format(current)))
> ? ? >? ? ? ? ?} else {
> ? ? >? ? ? ? ? ? ?thisComparison <- .all.equal.environment(target,
> current, ...)
> ? ? >? ? ? ? ? ? ?if (!isTRUE(thisComparison)) {
> ? ? >? ? ? ? ? ? ? ? ?msg <- c(msg, thisComparison)
> ? ? >? ? ? ? ? ? ?}
> ? ? >? ? ? ? ? ? ?parentComparison <- Recall(parent.env(target),
> ? ? > parent.env(current), ...)
> ? ? >? ? ? ? ? ? ?if (!isTRUE(parentComparison)) {
> ? ? >? ? ? ? ? ? ? ? ?msg <- c(msg, paste("<parent.env>",
> parentComparison))
> ? ? >? ? ? ? ? ? ?}
> ? ? >? ? ? ? ?}
> ? ? >? ? ? ? ?if (is.null(msg) || isTRUE(msg)) TRUE else msg
> ? ? >? ? ?}
> ? ? > }
>
> Thank you, Duncan and Bill (and Kevin for bringing up the
> topic).
>
> I agree? all.equal() should work better with functions,
>
> and I think probably it would make sense to define? all.equal.function()
> rather than put this into all.equal.default()
>
> However, it's not quite clear if it is always desirable to check the
> environments as well notably as that *is* done recursively.
>
> Bill, I'm sure you've noticed that we did write? all.equal.environment()
> to work recursively... Actually, I had worked quite a bit at
> that, too long ago to remember details, but the relevant svn log
> entry is
> ------------------------------------------------------------------------
> r66640 | maechler | 2014-09-18 22:10:20 +0200 (Thu, 18 Sep 2014) | 1
> line
>
> more sophisticated all.equal.environment(): no longer "simple"
> infinite recursions
> ------------------------------------------------------------------------
>
> Are you sure that code with the internal recursive do1()
> function should/could not be amended where needed?
>
> Martin
>
> ? ? > On Mon, Nov 30, 2020 at 10:42 AM Duncan Murdoch
> <murdoch.duncan at gmail.com <mailto:murdoch.duncan at gmail.com>>
> ? ? > wrote:
> ? ? >
> ? ? > > On 30/11/2020 1:05 p.m., Kevin Van Horn via R-devel wrote:
> ? ? > > > Consider the following code:
> ? ? > > >
> ? ? > > >? ? ? f <- function(x)function(y){x+y}
> ? ? > > >? ? ? all.equal(f(5), f(0))
> ? ? > > >
> ? ? > > > This returns TRUE, when it should return FALSE; I think
> it?s hard to
> ? ? > > make the case that f(5) and f(0) are ?approximately equal?
> in any
> ? ? > > meaningful sense. Digging into the code for all.equal(), I
> see that
> ? ? > > all.equal(f(5), f(0)) results in a call to
> all.equal.language(f(5), f(0)),
> ? ? > > which only compares the function texts for equality.
> ? ? > > >
> ? ? > > > If it is decided to leave this behavior as-is, then at
> least it should
> ? ? > > be documented. Currently I cannot find any documentation
> for all.equal
> ? ? > > applied to functions.
> ? ? > >
> ? ? > > Clearly it should also compare the environments of the two
> functions,
> ? ? > > then it would see a difference:
> ? ? > >
> ? ? > >? > all.equal(environment(f(5)), environment(f(0)))
> ? ? > > [1] "Component ?x?: Mean relative difference: 1"
> ? ? > >
> ? ? > > Changing the first few lines from
> ? ? > >
> ? ? > >? ? ? if (is.language(target) || is.function(target))
> ? ? > >? ? ? ? ? return(all.equal.language(target, current, ...))
> ? ? > >
> ? ? > > to
> ? ? > >
> ? ? > >? ? ? if (is.function(target)) {
> ? ? > >? ? ? ? ? msg <- all.equal.language(target, current, ...)
> ? ? > >? ? ? ? ? if (isTRUE(msg)) {
> ? ? > >? ? ? ? ? ? ? msg <- all.equal.environment(environment(target),
> ? ? > > environment(current), ...)
> ? ? > >? ? ? ? ? ? ? if (is.character(msg))
> ? ? > >? ? ? ? ? ? ? ? msg <- paste("Environments:", msg)
> ? ? > >? ? ? ? ? }
> ? ? > >? ? ? ? ? return(msg)
> ? ? > >? ? ? }
> ? ? > >? ? ? if (is.language(target))
> ? ? > >? ? ? ? ? return(all.equal.language(target, current, ...))
> ? ? > >
> ? ? > > would fix it.
> ? ? > >
> ? ? > > Duncan Murdoch
> ? ? > >
> ? ? > > ______________________________________________
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