[graalvm-users] Setting attributes inconsistencies

[Stepan]

This discussion made me realize the following issue: whatever is 
happening in the interop is not visible to R runtime, so if you assign 
the result of say "c(1,2,3)" to Ruby variable, R will still think that 
it's a temporary object and it is safe to reuse it for anything. 
Thinking about it now, FastR should mark all objects that were leaked to 
other languages and never reuse them. We'll get that fixed soon.

Stepan

On 07/07/18 00:03, Benoit Daloze wrote:
> It seems to me it's as Stepan said.
> R of course does not reassign Ruby variables.
> And most R operations might or not mutate the receiver in place, with
> the general model of mutating only if it's unobservable
> (it is observable here, `vec` is actually a second reference to the
> initial vector).
> 
> On Fri, Jul 6, 2018 at 11:31 PM, Chris Seaton <chris.seaton at oracle.com> wrote:
>> Maybe this is something to do with the `dim<-` method? I don’t know anything about R but I guess that’s called when you do `names(something) =`. Can you try making a simple test case that just tests that these kind of methods can be called correctly? Maybe something about it messes up the arguments?
>>
>> Chris
>>
>>> On 6 Jul 2018, at 17:41, Rodrigo Botafogo <rodrigo.a.botafogo at gmail.com> wrote:
>>>
>>> Hello,
>>>
>>> I'm trying to set attributes to an r object using interop.  For some attributes everything works fine and for others the attribute is not set.
>>>
>>> Here what I'm trying in R:
>>>
>>> R.eval(<<-R)
>>>    vect = c(1, 2, 3, 4, 5, 6);
>>>    names(vect) = c("a", "b", "c", "d", "e", "f");
>>>    print(vect);
>>>    dim(vect) = c(3, 2);
>>>    print(vect)
>>> R
>>>
>>> The first print show the names set:
>>>
>>> a b c d e f
>>> 1 2 3 4 5 6
>>>
>>> and the second print shows the dimension change.  Changing the "dim"
>>> attribute erases the names attribute:
>>>       [,1] [,2]
>>> [1,]    1    4
>>> [2,]    2    5
>>> [3,]    3    6
>>>
>>> Now, doing this using interop:
>>>
>>> # pp to allow printing: already reported bug
>>> pp = Polyglot.eval("R", "function(x) print(x)")
>>>
>>> vec = Polyglot.eval("R", "c").call(1, 2, 3, 4, 5, 6)
>>> nams = Polyglot.eval("R", "c").call("a", "b", "c", "d", "e", "f")
>>> Polyglot.eval("R", "`names<-`").call(vec, nams)
>>> pp.call(vec)
>>>
>>> this prints as expected the vector with the names attribute:
>>>
>>> a b c d e f
>>> 1 2 3 4 5 6
>>>
>>> dims = Polyglot.eval("R", "c").call(3, 2)
>>> Polyglot.eval("R", "`dim<-`").call(vec, dims)
>>> pp.call(vec)
>>>
>>> a b c d e f
>>> 1 2 3 4 5 6
>>>
>>> method dim<- does not seem to  have worked.  There is no error message or anything after calling `dim<-`
>>>
>>> Is this a bug or did I do something wrong here?  Its strange that some attributes work and others don't.
>>>
>>>
>>>
>>>
>>> --
>>> Rodrigo Botafogo
>>>
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>>> GraalVM-Users at oss.oracle.com
>>> https://oss.oracle.com/mailman/listinfo/graalvm-users
>>
>>
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