[Rd] bquote/evalq behavior changed in R-3.2.1

Dayne Filer
Wed, 15 Jul 2015 20:44:25 -0000

David,

If you are referring to the solution that would be:

rapply(list(test), eval, envir = fenv)

I thought I explained in the question that the above code does not work. It
does not throw an error, but the behavior is no different (at least in the
output or result). Using the above code still results in the x object not
being stored in fenv on 3.1.2.

Dayne

On Wed, Jul 15, 2015 at 4:40 PM, William Dunlap <wdunlap at tibco.com>
wrote:

> Another aspect of the change is (using TERR's RinR package):
> > options(REvaluators=list(makeREvaluator("R-3.1.3"),
>
makeREvaluator("R-3.2.0")))
> > RCompare(rapply(list(quote(function(x)x),list(quote(pi),quote(7-4))),
> function(arg)typeof(arg)))
>      R version 3.1.3 (2015-03-09) R version 3.2.0 (2015-04-16)
> [1,] [1] "closure" "double"       [1]
"language" "symbol"
> [2,] [3] "double"                 [3] "language"
>   $all.equal
>   $all.equal$`R version 3.1.3 (2015-03-09) vs. R version 3.2.0
> (2015-04-16)`
>   [1] "3 string mismatches"
>
> I prefer the new semantics, but it is a change.
>
>
>
> Bill Dunlap
> TIBCO Software
> wdunlap tibco.com
>
> On Wed, Jul 15, 2015 at 1:25 PM, David Winsemius <dwinsemius at
comcast.net>
> wrote:
>
>>
>> On Jul 15, 2015, at 12:51 PM, William Dunlap wrote:
>>
>> > I think rapply() was changed to act like lapply() in this respect.
>> >
>>
>> When I looked at the source of the difference, it was that typeof()
>> returned 'language' in 3.2.1, while it returned 'list'
in the earlier
>> version of R. The first check in rapply's code in both version was:
>>
>>  if (typeof(object) != "list")
>>         stop("'object' must be a list")
>>
>> Wrapping list() around the first argument and switching to using eval
>> with an expression-object rather than a call-object seemed to solve the
>> problem when this was posed as a question on StackOverflow, but Dayne
was
>> not happy with that solution for other reasons that he is not
describing.
>>
>> --
>> David.
>>
>> > In R-3.1.3 we got
>> > rapply(list(quote(1+myNumber)), evalq,
>> envir=list2env(list(myNumber=17)))
>> > #[1] 18
>> > rapply(list(quote(1+myNumber)), eval,
envir=list2env(list(myNumber=17)))
>> > #Error in (function (expr, envir = parent.frame(), enclos = if
>> > (is.list(envir) ||  :
>> >  object 'myNumber' not found
>> > lapply(list(quote(1+myNumber)), evalq,
>> envir=list2env(list(myNumber=17)))
>> > #Error in eval(substitute(expr), envir, enclos) : object
'X' not found
>> > lapply(list(quote(1+myNumber)), eval,
envir=list2env(list(myNumber=17)))
>> > #[[1]]
>> > #[1] 18
>> > while in R-3.2.0 we get
>> > rapply(list(quote(1+myNumber)), evalq,
>> envir=list2env(list(myNumber=17)))
>> > #Error in eval(substitute(expr), envir, enclos) : object
'X' not found
>> > rapply(list(quote(1+myNumber)), eval,
envir=list2env(list(myNumber=17)))
>> > #[1] 18
>> > lapply(list(quote(1+myNumber)), evalq,
>> envir=list2env(list(myNumber=17)))
>> > #Error in eval(substitute(expr), envir, enclos) : object
'X' not found
>> > lapply(list(quote(1+myNumber)), eval,
envir=list2env(list(myNumber=17)))
>> > #[[1]]
>> > #[1] 18
>> >
>> > Make the FUN argument function(arg)sys.call() to see some details
of the
>> > change.
>> >
>> >
>> > Bill Dunlap
>> > TIBCO Software
>> > wdunlap tibco.com
>> >
>> > On Wed, Jul 15, 2015 at 12:35 PM, Dayne Filer <dayne.filer at
gmail.com>
>> wrote:
>> >
>> >> In 3.1.2 eval does not store the result of the
bquote-generated call in
>> >> the given environment. Interestingly, in 3.2.1 eval does store
the
>> result
>> >> of the bquote-generated call in the given environment.
>> >>
>> >> In other words if I run the given example with eval rather
than evalq,
>> on
>> >> 3.1.2 "x" is never stored in "fenv," but
it is when I run the same
>> code on
>> >> 3.2.1. However, the given example stores "x" in
"fenv" on 3.1.2, but
>> throws
>> >> the error I gave when run on 3.2.1.
>> >>
>> >> To give credit, I received the idea for using evalq from SO:
>> >> http://stackoverflow.com/a/22559385
>> >>
>> >> Dayne
>> >>
>> >>
>> >> On Wed, Jul 15, 2015 at 3:29 PM, William Dunlap <wdunlap at
tibco.com>
>> wrote:
>> >>
>> >>> I am curious why you used evalq instead of eval in this
code.
>> >>>
>> >>> Bill Dunlap
>> >>> TIBCO Software
>> >>> wdunlap tibco.com
>> >>>
>> >>> On Wed, Jul 15, 2015 at 11:49 AM, Dayne Filer
<dayne.filer at gmail.com>
>> >>> wrote:
>> >>>
>> >>>> Hello,
>> >>>>
>> >>>> I upgraded from 3.1.2 to 3.2.1 and am receiving errors
on code that
>> >>>> worked
>> >>>> as I intended previously. Briefly, I am using bquote
to generate
>> >>>> expressions to modify data.table objects within a
function, so I
>> need
>> >>>> the
>> >>>> changes to actually be stored in the given
environment. Previously, I
>> >>>> used
>> >>>> code like the following:
>> >>>>
>> >>>> test <- list(bquote(x <- 10))
>> >>>> fenv <- environment()
>> >>>> rapply(test, evalq, envir = fenv)
>> >>>>
>> >>>> Although the code in the example above is much
simpler, it shows the
>> >>>> problem. On 3.1.2 the expression is evaluated and x is
stored as 10
>> in
>> >>>> the
>> >>>> given environment, fenv. In 3.2.1 the code throws an
error:
>> >>>>
>> >>>> Error in eval(substitute(expr), envir, enclos) :
object 'X' not found
>> >>>>
>> >>>> I could not find anything in the release notes that
would explain
>> this
>> >>>> change. Changing evalq to eval works in 3.2.1, but
eval does not
>> store x
>> >>>> in
>> >>>> the given environment in 3.1.2.
>> >>>>
>> >>>> Thanks,
>> >>>>
>> >>>> Dayne
>> >>>>
>> >>>>        [[alternative HTML version deleted]]
>> >>>>
>> >>>> ______________________________________________
>> >>>> R-devel at r-project.org mailing list
>> >>>> https://stat.ethz.ch/mailman/listinfo/r-devel
>> >>>>
>> >>>
>> >>>
>> >>
>> >
>> >       [[alternative HTML version deleted]]
>> >
>> > ______________________________________________
>> > R-devel at r-project.org mailing list
>> > https://stat.ethz.ch/mailman/listinfo/r-devel
>>
>> David Winsemius
>> Alameda, CA, USA