> > > > >>> That is not true at all - the presence of header does not constitute > >> declaration of something as the R API. There are cases where internal > >> functions are in the headers for historical or other reasons since the > >> headers are used both for the internal implementation and packages. > That's > >> why this is in R-exts under "The R API: entry points for C code": > >>> > >>> If I understand your point correctly, does this mean that > >> Rf_allocVector() is not part of the "official" R API? It does not > appear to > >> be documented in the "The R API: entry points for C code" section. > >>> > >> > >> It does, obviously: > >> https://cran.r-project.org/doc/manuals/R-exts.html#Allocating-storage-1 > > > > > > I'm just trying to understand the precise definition of the official API > > here. So it's any function mentioned in R-exts, regardless of which > section > > it appears in? > > > > Does this sentence imply that all functions starting with alloc* are part > > of the official API? > > > > Again, I can only quote the R-exts (few lines below the previous "The R > API" quote): > > > We can classify the entry points as > API > Entry points which are documented in this manual and declared in an > installed header file. These can be used in distributed packages and will > only be changed after deprecation. > > > It says "in this manual" - I don't see anywhere restriction on a > particular section of the manual, so I really don't see why you would think > that allocation is not part on the API. >Because you mentioned that section explicitly earlier in the thread. This obviously seems clear to you, but it's not at all clear to me and I suspect many of the wider community. It's frustrating because we are trying our best to do what y'all want us to do, but it feels like we keep getting the rug pulled out from under us with very little notice, and then have to spend a large amount of time figuring out workarounds. That is at least feasible for my team since we have multiple talented folks who are paid full-time to work on R, but it's a huge struggle for most people who are generally maintaining packages in their spare time. For the purposes of this discussion could you please "documented in the manual" means? For example, this line mentions allocXxx functions: "There are quite a few allocXxx functions defined in Rinternals.h?you may want to explore them.". Does that imply that they are documented and free to use? And in general, I'd urge R Core to make an explicit list of functions that you consider to be part of the exported API, and then grandfather in packages that used those functions prior to learning that we weren't supposed to. Hadley -- http://hadley.nz [[alternative HTML version deleted]]
> And in general, I'd urge R Core to make an explicit list of functions thatyou consider to be part of the exported API While I believe R Core is in the process of such clarification, I'd also vote for this. Now that WRE has "experimental" category, and if we take the current definition of "documented in the manual" literally, an "experimental" entry point cannot be documented because the entry point would promote to an "API" for the obvious reason. It would sound funny that you cannot write precautionary statements on experimental entry points just because of the very definition of "experimental". So, I agree R should have the explicit list. I'd add that R should also define a process on how to stabilize an "experimental" or "public" entry point into an "API". For example, Rust language has such a process [1]. After a feature is introduced as unstable, a "tracking issue" is filed and the related problems are reported or linked to it. Users can know what are the remaining problems before getting stabilized, and, if they have strong will, they can contribute to resolving such blockers. Similarly, if we can track the unresolved problems of each non-API, we might be able to help the R core team more smoothly. Best, Yutani [1]: https://rustc-dev-guide.rust-lang.org/stabilization_guide.html 2024?4?24?(?) 21:55 Hadley Wickham <h.wickham at gmail.com>:> > > > > > > > >>> That is not true at all - the presence of header does not constitute > > >> declaration of something as the R API. There are cases where internal > > >> functions are in the headers for historical or other reasons since the > > >> headers are used both for the internal implementation and packages. > > That's > > >> why this is in R-exts under "The R API: entry points for C code": > > >>> > > >>> If I understand your point correctly, does this mean that > > >> Rf_allocVector() is not part of the "official" R API? It does not > > appear to > > >> be documented in the "The R API: entry points for C code" section. > > >>> > > >> > > >> It does, obviously: > > >> > https://cran.r-project.org/doc/manuals/R-exts.html#Allocating-storage-1 > > > > > > > > > I'm just trying to understand the precise definition of the official > API > > > here. So it's any function mentioned in R-exts, regardless of which > > section > > > it appears in? > > > > > > Does this sentence imply that all functions starting with alloc* are > part > > > of the official API? > > > > > > > Again, I can only quote the R-exts (few lines below the previous "The R > > API" quote): > > > > > > We can classify the entry points as > > API > > Entry points which are documented in this manual and declared in an > > installed header file. These can be used in distributed packages and will > > only be changed after deprecation. > > > > > > It says "in this manual" - I don't see anywhere restriction on a > > particular section of the manual, so I really don't see why you would > think > > that allocation is not part on the API. > > > > Because you mentioned that section explicitly earlier in the thread. This > obviously seems clear to you, but it's not at all clear to me and I suspect > many of the wider community. It's frustrating because we are trying > our best to do what y'all want us to do, but it feels like we keep getting > the rug pulled out from under us with very little notice, and then have to > spend a large amount of time figuring out workarounds. That is at least > feasible for my team since we have multiple talented folks who are paid > full-time to work on R, but it's a huge struggle for most people who are > generally maintaining packages in their spare time. > > For the purposes of this discussion could you please "documented in the > manual" means? For example, this line mentions allocXxx functions: "There > are quite a few allocXxx functions defined in Rinternals.h?you may want to > explore them.". Does that imply that they are documented and free to use? > > And in general, I'd urge R Core to make an explicit list of functions that > you consider to be part of the exported API, and then grandfather in > packages that used those functions prior to learning that we weren't > supposed to. > > Hadley > > > -- > http://hadley.nz > > [[alternative HTML version deleted]] > > ______________________________________________ > R-devel at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel >[[alternative HTML version deleted]]
A few more thoughts based on a simple question: how do you determine the length of a vector? Rf_length() is used in example code in R-exts, but I don't think it's formally documented anywhere (although it's possible I missed it). Is using in an example sufficient to consider a function to be part of the public API? If so, SET_TYPEOF() is used in a number of examples, and hence used by CRAN packages, but is no longer considered part of the public API. Rf_xlength() doesn't appear to be mentioned anywhere in R-exts. Does this imply that long vectors are not part of the exported API? Or is there some other way we should be determining the length of such vectors? Are the macro variants LENGTH and XLENGTH part of the exported API? Are we supposed to use them or avoid them? Relatedly, I presume that LOGICAL() is the way we're supposed to extract logical values from a vector, but it isn't documented in R-exts, suggesting that it's not part of the public API? --- It's also worth pointing out where R-exts does well, with the documentation of utility functions ( https://cran.r-project.org/doc/manuals/R-exts.html#Utility-functions). I think this is what most people would consider documentation to imply, i.e. a list of input arguments/types, the output type, and basic notes on their operation. --- Finally, it's worth noting that there's some lingering ill feelings over how the connections API was treated. It was documented in R-exts only to be later removed, including expunging mentions of it in the news. That's obviously water under the bridge, but I do believe that there is the potential for the R core team to build goodwill with the community if they are willing to engage a bit more with the users of their APIs. Hadley [[alternative HTML version deleted]]
> On Apr 25, 2024, at 12:55 AM, Hadley Wickham <h.wickham at gmail.com> wrote: > > > > >>> That is not true at all - the presence of header does not constitute > >> declaration of something as the R API. There are cases where internal > >> functions are in the headers for historical or other reasons since the > >> headers are used both for the internal implementation and packages. That's > >> why this is in R-exts under "The R API: entry points for C code": > >>> > >>> If I understand your point correctly, does this mean that > >> Rf_allocVector() is not part of the "official" R API? It does not appear to > >> be documented in the "The R API: entry points for C code" section. > >>> > >> > >> It does, obviously: > >> https://cran.r-project.org/doc/manuals/R-exts.html#Allocating-storage-1 > > > > > > I'm just trying to understand the precise definition of the official API > > here. So it's any function mentioned in R-exts, regardless of which section > > it appears in? > > > > Does this sentence imply that all functions starting with alloc* are part > > of the official API? > > > > Again, I can only quote the R-exts (few lines below the previous "The R API" quote): > > > We can classify the entry points as > API > Entry points which are documented in this manual and declared in an installed header file. These can be used in distributed packages and will only be changed after deprecation. > > > It says "in this manual" - I don't see anywhere restriction on a particular section of the manual, so I really don't see why you would think that allocation is not part on the API. > > Because you mentioned that section explicitly earlier in the thread. This obviously seems clear to you, but it's not at all clear to me and I suspect many of the wider community. It's frustrating because we are trying our best to do what y'all want us to do, but it feels like we keep getting the rug pulled out from under us with very little notice, and then have to spend a large amount of time figuring out workarounds. That is at least feasible for my team since we have multiple talented folks who are paid full-time to work on R, but it's a huge struggle for most people who are generally maintaining packages in their spare time. >I must be missing something here since I have no idea what you are talking about. The whole point if a stable API is that no rugs are pulled, so in fact it's exactly the opposite of what you claim - the notice is at least a year due to the release cycle, typically more. Unlike many other languages and ecosystems, R public API does not change very often - and R-core is thinking hard about making breaking changes if at all. In fact, I hear more complaints that the API does NOT change and we are too conservative, precisely because we want to avoid unnecessary breakage. I will not further comment here - all I did was to point out the relevant text from R-exts which is the canonical source of information. If you have issues, find some parts unclear and want to improve the documentation, I would like to invite you to contribute constructively, propose changes, submit patches. The R-exts document has been around for decades, so it seem implausible that all of sudden it is being misunderstood the way you portrayed it, but it is certainly a good idea to improve documentation so contributions are welcome. Cheers, Simon
iuke-tier@ey m@iii@g oii uiow@@edu
2024-Apr-24 20:31 UTC
[Rd] [External] Re: Is ALTREP "non-API"?
On Wed, 24 Apr 2024, Hadley Wickham wrote:>> >> >> >>>>> That is not true at all - the presence of header does not constitute >>>> declaration of something as the R API. There are cases where internal >>>> functions are in the headers for historical or other reasons since the >>>> headers are used both for the internal implementation and packages. >> That's >>>> why this is in R-exts under "The R API: entry points for C code": >>>>> >>>>> If I understand your point correctly, does this mean that >>>> Rf_allocVector() is not part of the "official" R API? It does not >> appear to >>>> be documented in the "The R API: entry points for C code" section. >>>>> >>>> >>>> It does, obviously: >>>> https://cran.r-project.org/doc/manuals/R-exts.html#Allocating-storage-1 >>> >>> >>> I'm just trying to understand the precise definition of the official API >>> here. So it's any function mentioned in R-exts, regardless of which >> section >>> it appears in? >>> >>> Does this sentence imply that all functions starting with alloc* are part >>> of the official API? >>> >> >> Again, I can only quote the R-exts (few lines below the previous "The R >> API" quote): >> >> >> We can classify the entry points as >> API >> Entry points which are documented in this manual and declared in an >> installed header file. These can be used in distributed packages and will >> only be changed after deprecation. >> >> >> It says "in this manual" - I don't see anywhere restriction on a >> particular section of the manual, so I really don't see why you would think >> that allocation is not part on the API. >> > > Because you mentioned that section explicitly earlier in the thread. This > obviously seems clear to you, but it's not at all clear to me and I suspect > many of the wider community. It's frustrating because we are trying > our best to do what y'all want us to do, but it feels like we keep getting > the rug pulled out from under us with very little notice, and then have to > spend a large amount of time figuring out workarounds.Please try to keep this discussion non-adversarial.> That is at least > feasible for my team since we have multiple talented folks who are paid > full-time to work on R, but it's a huge struggle for most people who are > generally maintaining packages in their spare time.As you well know, almost all R-core members are also trying to maintain and improve R in their spare time. Good for folks to keep in mind before demanding R-core do X, Y, or Z for you.> For the purposes of this discussion could you please "documented in the > manual" means? For example, this line mentions allocXxx functions: "There > are quite a few allocXxx functions defined in Rinternals.h?you may want to > explore them.". Does that imply that they are documented and free to use?Where we are now in terms of what package authors can use to write R extensions has evolved organically over many years. The current state is certainly not ideal: There are entry points in installed headers that might be available; but to find out if they are in fact available requires reading prose text in the header files and in WRE. Trying to fine-tune wording in WRE, or add a lot of additional entries is not really a good or realistic way forward: WRE is both documentation and tutorial and more legalistic language/more complete coverage would make it less readable and still not guarantee completeness or clarity. We would be better off (in my view, not necessarily shared by others in R-core) if we could get to a point where: all entry points listed in installed header files can be used in packages, at least with some caveats; the caveats are expressed in a standard way that is searchable, e.g. with a standardized comment syntax at the header file or individual declaration level. In principle this is achievable, but getting there from where we are now is a lot of work. There are some 500 entry points in the R shared library that are in the installed headers but not mentioned in WRE. These would need to be reviewed and adjusted. My guess is about a third are fine and intended to be API-stable, another third are not used in packages and don't need to be in public headers. The remainder are things that may be used in current packages but really should not be, for example because they expose internal data in ways that can cause segfaults or they make it difficult to implement performance improvements in the base engine. Sorting through these and working with package authors to find alternate, safer options takes a lot of time (see 'spare time' above) and energy (some package authors are easier to work with than others). Several of us have taken cracks at moving this forward from time to time, but it rarely gets to the top of anyone's priority list.> And in general, I'd urge R Core to make an explicit list of functions that > you consider to be part of the exported API, and then grandfather in > packages that used those functions prior to learning that we weren't > supposed to.Making a list and hoping that it will remain up to date is not realistic. The only way that would work reliably is if the list could be programmatically generated, for example by parsing installed headers for declarations and caveats as above. Which would be possible with changes like the ones listed above. Best, luke> > Hadley > > >-- Luke Tierney Ralph E. Wareham Professor of Mathematical Sciences University of Iowa Phone: 319-335-3386 Department of Statistics and Fax: 319-335-3017 Actuarial Science 241 Schaeffer Hall email: luke-tierney at uiowa.edu Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu/