Re: [Rd] [External] R C api for 'inherits' S3 and S4 objects
Thank you all for your valuable comments.
Best,
Jan
On Fri, Nov 1, 2019 at 8:15 PM Tierney, Luke wrote:
>
> On Fri, 1 Nov 2019, Jan Gorecki wrote:
>
> > Thank you Luke.
> > That is why I don't use Rf_inherits but INHERITS which does not
> > allocate, provided in the email body.
>
> Your definition can allocate because STING_ELT can allocate.
> getAttrib can GC in general. Currently it would not GC or allocate in
> this case, but this could change.
>
> You can't assume thread-safety for calls into the R API, or any API
> for that matter, unless they are documented to be thread-safe.
>
> You would be better off using Rf_inherits as it does not make the
> assumption that you can use pointer comparisons to check for identical
> strings. CHARSXPs are almost always cached but they are not
> guaranteed to be, and the caching strategy might change in the future.
>
> Best,
>
> luke
>
> > I cannot do similarly for S4 classes, thus asking for some API for that.
> >
> > On Fri, Nov 1, 2019 at 5:56 PM Tierney, Luke wrote:
> >>
> >> On Fri, 1 Nov 2019, Jan Gorecki wrote:
> >>
> >>> Dear R developers,
> >>>
> >>> Motivated by discussion about checking inheritance of S3 and S4
> >>> objects (in head matrix/array topic) I would light to shed some light
> >>> on a minor gap about that matter in R C API.
> >>> Currently we are able to check inheritance for S3 class objects from C
> >>> in a robust way (no allocation, thread safe). This is unfortunately
> >>
> >> Your premise is not correct. Rf_inherits will not GC but it can
> >> allocate and is not thread safe.
> >>
> >> Best,
> >>
> >> luke
> >>
> >>> not possible for S4 classes. I would kindly request new function in R
> >>> C api so it can be achieved for S4 classes with no risk of allocation.
> >>> For reference mentioned functions below. Thank you.
> >>> Jan Gorecki
> >>>
> >>> // S3 inheritance
> >>> bool INHERITS(SEXP x, SEXP char_) {
> >>> SEXP klass;
> >>> if (isString(klass = getAttrib(x, R_ClassSymbol))) {
> >>>for (int i=0; i >>> if (STRING_ELT(klass, i) == char_) return true;
> >>>}
> >>> }
> >>> return false;
> >>> }
> >>> // S4 inheritance
> >>> bool Rinherits(SEXP x, SEXP char_) {
> >>> SEXP vec = PROTECT(ScalarString(char_));
> >>> SEXP call = PROTECT(lang3(sym_inherits, x, vec));
> >>> bool ans = LOGICAL(eval(call, R_GlobalEnv))[0]==1;
> >>> UNPROTECT(2);
> >>> return ans;
> >>> }
> >>>
> >>> __
> >>> R-devel@r-project.org mailing list
> >>> https://stat.ethz.ch/mailman/listinfo/r-devel
> >>>
> >>
> >> --
> >> Luke Tierney
> >> Ralph E. Wareham Professor of Mathematical Sciences
> >> University of Iowa Phone: 319-335-3386
> >> Department of Statistics andFax: 319-335-3017
> >> Actuarial Science
> >> 241 Schaeffer Hall email: luke-tier...@uiowa.edu
> >> Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu
> >
>
> --
> Luke Tierney
> Ralph E. Wareham Professor of Mathematical Sciences
> University of Iowa Phone: 319-335-3386
> Department of Statistics andFax: 319-335-3017
> Actuarial Science
> 241 Schaeffer Hall email: luke-tier...@uiowa.edu
> Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu
__
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Re: [Rd] [External] R C api for 'inherits' S3 and S4 objects
On Fri, 1 Nov 2019, Jan Gorecki wrote:
> Thank you Luke.
> That is why I don't use Rf_inherits but INHERITS which does not
> allocate, provided in the email body.
Your definition can allocate because STING_ELT can allocate.
getAttrib can GC in general. Currently it would not GC or allocate in
this case, but this could change.
You can't assume thread-safety for calls into the R API, or any API
for that matter, unless they are documented to be thread-safe.
You would be better off using Rf_inherits as it does not make the
assumption that you can use pointer comparisons to check for identical
strings. CHARSXPs are almost always cached but they are not
guaranteed to be, and the caching strategy might change in the future.
Best,
luke
> I cannot do similarly for S4 classes, thus asking for some API for that.
>
> On Fri, Nov 1, 2019 at 5:56 PM Tierney, Luke wrote:
>>
>> On Fri, 1 Nov 2019, Jan Gorecki wrote:
>>
>>> Dear R developers,
>>>
>>> Motivated by discussion about checking inheritance of S3 and S4
>>> objects (in head matrix/array topic) I would light to shed some light
>>> on a minor gap about that matter in R C API.
>>> Currently we are able to check inheritance for S3 class objects from C
>>> in a robust way (no allocation, thread safe). This is unfortunately
>>
>> Your premise is not correct. Rf_inherits will not GC but it can
>> allocate and is not thread safe.
>>
>> Best,
>>
>> luke
>>
>>> not possible for S4 classes. I would kindly request new function in R
>>> C api so it can be achieved for S4 classes with no risk of allocation.
>>> For reference mentioned functions below. Thank you.
>>> Jan Gorecki
>>>
>>> // S3 inheritance
>>> bool INHERITS(SEXP x, SEXP char_) {
>>> SEXP klass;
>>> if (isString(klass = getAttrib(x, R_ClassSymbol))) {
>>>for (int i=0; i>> if (STRING_ELT(klass, i) == char_) return true;
>>>}
>>> }
>>> return false;
>>> }
>>> // S4 inheritance
>>> bool Rinherits(SEXP x, SEXP char_) {
>>> SEXP vec = PROTECT(ScalarString(char_));
>>> SEXP call = PROTECT(lang3(sym_inherits, x, vec));
>>> bool ans = LOGICAL(eval(call, R_GlobalEnv))[0]==1;
>>> UNPROTECT(2);
>>> return ans;
>>> }
>>>
>>> __
>>> R-devel@r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>>
>>
>> --
>> Luke Tierney
>> Ralph E. Wareham Professor of Mathematical Sciences
>> University of Iowa Phone: 319-335-3386
>> Department of Statistics andFax: 319-335-3017
>> Actuarial Science
>> 241 Schaeffer Hall email: luke-tier...@uiowa.edu
>> Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu
>
--
Luke Tierney
Ralph E. Wareham Professor of Mathematical Sciences
University of Iowa Phone: 319-335-3386
Department of Statistics andFax: 319-335-3017
Actuarial Science
241 Schaeffer Hall email: luke-tier...@uiowa.edu
Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu
__
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
Re: [Rd] [External] R C api for 'inherits' S3 and S4 objects
Note that your desire is by definition impossible - as your example also shows
checking for S4 inheritance involves evaluation and thus allocation which
cannot be avoided by the dynamic design of S4 inheritance.
Cheers,
Simon
> On Nov 1, 2019, at 9:23 AM, Jan Gorecki wrote:
>
> Thank you Luke.
> That is why I don't use Rf_inherits but INHERITS which does not
> allocate, provided in the email body.
> I cannot do similarly for S4 classes, thus asking for some API for that.
>
> On Fri, Nov 1, 2019 at 5:56 PM Tierney, Luke wrote:
>>
>> On Fri, 1 Nov 2019, Jan Gorecki wrote:
>>
>>> Dear R developers,
>>>
>>> Motivated by discussion about checking inheritance of S3 and S4
>>> objects (in head matrix/array topic) I would light to shed some light
>>> on a minor gap about that matter in R C API.
>>> Currently we are able to check inheritance for S3 class objects from C
>>> in a robust way (no allocation, thread safe). This is unfortunately
>>
>> Your premise is not correct. Rf_inherits will not GC but it can
>> allocate and is not thread safe.
>>
>> Best,
>>
>> luke
>>
>>> not possible for S4 classes. I would kindly request new function in R
>>> C api so it can be achieved for S4 classes with no risk of allocation.
>>> For reference mentioned functions below. Thank you.
>>> Jan Gorecki
>>>
>>> // S3 inheritance
>>> bool INHERITS(SEXP x, SEXP char_) {
>>> SEXP klass;
>>> if (isString(klass = getAttrib(x, R_ClassSymbol))) {
>>> for (int i=0; i>> if (STRING_ELT(klass, i) == char_) return true;
>>> }
>>> }
>>> return false;
>>> }
>>> // S4 inheritance
>>> bool Rinherits(SEXP x, SEXP char_) {
>>> SEXP vec = PROTECT(ScalarString(char_));
>>> SEXP call = PROTECT(lang3(sym_inherits, x, vec));
>>> bool ans = LOGICAL(eval(call, R_GlobalEnv))[0]==1;
>>> UNPROTECT(2);
>>> return ans;
>>> }
>>>
>>> __
>>> R-devel@r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>>
>>
>> --
>> Luke Tierney
>> Ralph E. Wareham Professor of Mathematical Sciences
>> University of Iowa Phone: 319-335-3386
>> Department of Statistics andFax: 319-335-3017
>>Actuarial Science
>> 241 Schaeffer Hall email: luke-tier...@uiowa.edu
>> Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu
>
> __
> R-devel@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>
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Re: [Rd] [External] R C api for 'inherits' S3 and S4 objects
AFAIR getAttrib() can allocate as well. Also, R API functions that do
not allocate today, may allocate in the future.
Gabor
On Fri, Nov 1, 2019 at 1:24 PM Jan Gorecki wrote:
>
> Thank you Luke.
> That is why I don't use Rf_inherits but INHERITS which does not
> allocate, provided in the email body.
> I cannot do similarly for S4 classes, thus asking for some API for that.
>
> On Fri, Nov 1, 2019 at 5:56 PM Tierney, Luke wrote:
> >
> > On Fri, 1 Nov 2019, Jan Gorecki wrote:
> >
> > > Dear R developers,
> > >
> > > Motivated by discussion about checking inheritance of S3 and S4
> > > objects (in head matrix/array topic) I would light to shed some light
> > > on a minor gap about that matter in R C API.
> > > Currently we are able to check inheritance for S3 class objects from C
> > > in a robust way (no allocation, thread safe). This is unfortunately
> >
> > Your premise is not correct. Rf_inherits will not GC but it can
> > allocate and is not thread safe.
> >
> > Best,
> >
> > luke
> >
> > > not possible for S4 classes. I would kindly request new function in R
> > > C api so it can be achieved for S4 classes with no risk of allocation.
> > > For reference mentioned functions below. Thank you.
> > > Jan Gorecki
> > >
> > > // S3 inheritance
> > > bool INHERITS(SEXP x, SEXP char_) {
> > > SEXP klass;
> > > if (isString(klass = getAttrib(x, R_ClassSymbol))) {
> > >for (int i=0; i > > if (STRING_ELT(klass, i) == char_) return true;
> > >}
> > > }
> > > return false;
> > > }
> > > // S4 inheritance
> > > bool Rinherits(SEXP x, SEXP char_) {
> > > SEXP vec = PROTECT(ScalarString(char_));
> > > SEXP call = PROTECT(lang3(sym_inherits, x, vec));
> > > bool ans = LOGICAL(eval(call, R_GlobalEnv))[0]==1;
> > > UNPROTECT(2);
> > > return ans;
> > > }
> > >
> > > __
> > > R-devel@r-project.org mailing list
> > > https://stat.ethz.ch/mailman/listinfo/r-devel
> > >
> >
> > --
> > Luke Tierney
> > Ralph E. Wareham Professor of Mathematical Sciences
> > University of Iowa Phone: 319-335-3386
> > Department of Statistics andFax: 319-335-3017
> > Actuarial Science
> > 241 Schaeffer Hall email: luke-tier...@uiowa.edu
> > Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu
>
> __
> R-devel@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
__
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Re: [Rd] [External] R C api for 'inherits' S3 and S4 objects
Thank you Luke.
That is why I don't use Rf_inherits but INHERITS which does not
allocate, provided in the email body.
I cannot do similarly for S4 classes, thus asking for some API for that.
On Fri, Nov 1, 2019 at 5:56 PM Tierney, Luke wrote:
>
> On Fri, 1 Nov 2019, Jan Gorecki wrote:
>
> > Dear R developers,
> >
> > Motivated by discussion about checking inheritance of S3 and S4
> > objects (in head matrix/array topic) I would light to shed some light
> > on a minor gap about that matter in R C API.
> > Currently we are able to check inheritance for S3 class objects from C
> > in a robust way (no allocation, thread safe). This is unfortunately
>
> Your premise is not correct. Rf_inherits will not GC but it can
> allocate and is not thread safe.
>
> Best,
>
> luke
>
> > not possible for S4 classes. I would kindly request new function in R
> > C api so it can be achieved for S4 classes with no risk of allocation.
> > For reference mentioned functions below. Thank you.
> > Jan Gorecki
> >
> > // S3 inheritance
> > bool INHERITS(SEXP x, SEXP char_) {
> > SEXP klass;
> > if (isString(klass = getAttrib(x, R_ClassSymbol))) {
> >for (int i=0; i > if (STRING_ELT(klass, i) == char_) return true;
> >}
> > }
> > return false;
> > }
> > // S4 inheritance
> > bool Rinherits(SEXP x, SEXP char_) {
> > SEXP vec = PROTECT(ScalarString(char_));
> > SEXP call = PROTECT(lang3(sym_inherits, x, vec));
> > bool ans = LOGICAL(eval(call, R_GlobalEnv))[0]==1;
> > UNPROTECT(2);
> > return ans;
> > }
> >
> > __
> > R-devel@r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-devel
> >
>
> --
> Luke Tierney
> Ralph E. Wareham Professor of Mathematical Sciences
> University of Iowa Phone: 319-335-3386
> Department of Statistics andFax: 319-335-3017
> Actuarial Science
> 241 Schaeffer Hall email: luke-tier...@uiowa.edu
> Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu
__
R-devel@r-project.org mailing list
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Re: [Rd] [External] R C api for 'inherits' S3 and S4 objects
On Fri, 1 Nov 2019, Jan Gorecki wrote:
> Dear R developers,
>
> Motivated by discussion about checking inheritance of S3 and S4
> objects (in head matrix/array topic) I would light to shed some light
> on a minor gap about that matter in R C API.
> Currently we are able to check inheritance for S3 class objects from C
> in a robust way (no allocation, thread safe). This is unfortunately
Your premise is not correct. Rf_inherits will not GC but it can
allocate and is not thread safe.
Best,
luke
> not possible for S4 classes. I would kindly request new function in R
> C api so it can be achieved for S4 classes with no risk of allocation.
> For reference mentioned functions below. Thank you.
> Jan Gorecki
>
> // S3 inheritance
> bool INHERITS(SEXP x, SEXP char_) {
> SEXP klass;
> if (isString(klass = getAttrib(x, R_ClassSymbol))) {
>for (int i=0; i if (STRING_ELT(klass, i) == char_) return true;
>}
> }
> return false;
> }
> // S4 inheritance
> bool Rinherits(SEXP x, SEXP char_) {
> SEXP vec = PROTECT(ScalarString(char_));
> SEXP call = PROTECT(lang3(sym_inherits, x, vec));
> bool ans = LOGICAL(eval(call, R_GlobalEnv))[0]==1;
> UNPROTECT(2);
> return ans;
> }
>
> __
> R-devel@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>
--
Luke Tierney
Ralph E. Wareham Professor of Mathematical Sciences
University of Iowa Phone: 319-335-3386
Department of Statistics andFax: 319-335-3017
Actuarial Science
241 Schaeffer Hall email: luke-tier...@uiowa.edu
Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu
__
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