From jmc4 at stanford.edu  Thu Oct 21 19:26:20 2010
From: jmc4 at stanford.edu (John Chambers)
Date: Thu, 21 Oct 2010 10:26:20 -0700
Subject: [Rd] new.env does not recognize parents from
	subclassesof	"environment"
In-Reply-To: <77EB52C6DD32BA4D87471DCD70C8D7000393EF21@NA-PA-VBE03.na.tibco.com>
References: <cpnwrpdgod9.fsf@gmail.com> <4CBF2514.8050409@stanford.edu>
	<cpnzku71qpq.fsf@gmail.com>
	<77EB52C6DD32BA4D87471DCD70C8D7000393EF21@NA-PA-VBE03.na.tibco.com>
Message-ID: <4CC077BC.5050209@stanford.edu>

  This is a problem related to the introduction of exact= into the [[ 
and [[<- functions. As Bill says, the current method misuses 
eval.parent() when that argument is added.

However, a simpler and more efficient solution is to migrate the checks 
for subclasses of "environment" used in other base code into the code 
for [[<- (and for $<-), at which point the methods for these functions 
are no longer needed.

A solution on these lines is being tested now and will find its way into 
r-devel and 2.12 patched.

One other point about the original posting:

Please don't use constructions like env at .xData. This depends on the 
current implementation and is not part of the user-level definition. Use 
as(env, "environment") or equivalent. (In this case, the assignment of 
the object's own environment was irrelevant to the error.)

John Chambers

On 10/21/10 9:21 AM, William Dunlap wrote:
> The traceback looks very similar to a problem
> in R 2.11.1 reported earlier this month by Troy Robertson.
>    >  From: r-devel-bounces at r-project.org
>    >  [mailto:r-devel-bounces at r-project.org] On Behalf Of Troy Robertson
>    >  Sent: Wednesday, October 06, 2010 6:13 PM
>    >  To: 'r-devel at R-project.org'
>    >  Subject: Re: [Rd] Recursion error after upgrade to
>    >  R_2.11.1[Sec=Unclassified]
> It was due to a miscount of how many frames to go
> up before evaluating an expression in
> getMethod("[[<-",".environment") because setMethod()
> introduced a local function in the new method.
>
> Bill Dunlap
> Spotfire, TIBCO Software
> wdunlap tibco.com
>
>> -----Original Message-----
>> From: r-devel-bounces at r-project.org
>> [mailto:r-devel-bounces at r-project.org] On Behalf Of Vitally S.
>> Sent: Thursday, October 21, 2010 9:00 AM
>> To: John Chambers
>> Cc: r-devel at r-project.org
>> Subject: Re: [Rd] new.env does not recognize parents from
>> subclassesof "environment"
>>
>>
>>
>> Here is an infinite recursion error  which occurs only with S4
>> subclasses assignment.
>>
>>   setClass("myenv", contains = "environment")
>> #[1] "myenv"
>>   env<- new("myenv")
>>   env[[".me"]]<- ?
>> #Error: evaluation nested too deeply: infinite recursion /
>> options(expressions=)?
>>
>>
>> With basic types it works as expected:
>>
>> env1<- new.env()
>> env1[[".me"]]<- env1
>>
>> May be this is related to active bindings that you mentioned,
>>   but I am still
>> reporting it here.
>>
>> Vitally.
>>
>>
>>>   Thanks for the report.  Should now be fixed in r-devel and
>> 2.12 patched (rev 53383).
>>> Please do report any cases where a subclass of environment
>> doesn't work.  There are some known cases in locking and
>>> active binding, that will be fixed in due course.
>>>
>>> The workaround for any such problem is usually as.environment().
>>>
>>> On 10/20/10 3:17 AM, Vitaly S. wrote:
>>>> Dear Developers,
>>>>
>>>> A lot has been changed in the R12.0 with respect to
>> behavior of "environment"
>>>> subclasses.  Many thanks for that.
>>>>
>>>> One small irregularity, though; new.env does not allow the
>> parent to be from S4
>>>> subclass.
>>>>
>>>>
>>>>> setClass("myenv", contains="environment")
>>>> [1] "myenv"
>>>>> new.env(parent=new("myenv"))
>>>> Error in new.env(parent = new("myenv")) : 'enclos' must be
>> an environment
>>>> I wonder if this is a "planed" behavior.
>>>>
>>>> The use of .xData  slot obviously works:
>>>>> new.env(parent=new("myenv")@.xData)
>>>> <environment: 063bb9e8>
>>>> Thanks,
>>>> Vitaly.
>>>>
>>>> ______________________________________________
>>>> R-devel at r-project.org mailing list
>>>> https://stat.ethz.ch/mailman/listinfo/r-devel>
>> ______________________________________________
>> R-devel at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>



[Rd] new.env does not recognize parents from subclassesof "environment"
John Chambers