Open discussion on renaming polars classes

[sorhawell]

I suggest to prefix all polars classes Polars, examples would be PolarsDataFrame PolarsSeries PolarsDataType

Pros:

• Reduces risk of namespace collision with other R packages

• Improves readability of rust code as currently native rust-polars struct and wrapper structs are named the same:

  readability example of current naming: rust-polars LazyFrame in a wrapper struct named LazyFrame. This can be a confusing to read, also the compiler error can be confusing.

  

Cons:

• class/struct names become a bit long

  What naming do you (anyone) prefer/suggest? Should we rename? Prefixed RPolars?

Bonus info

• Camel case is the only (unless explicitly disabled) allowed naming style for structs on rust side.
• Currently, extendr can only name R side auto generated class the same as rust side wrapper structs.
• Since r-polars only uses 2 structs + 1 class from rust-polars to public R, whereas py-polars use 2 structs + 2 classes, the final public R side class name most be the same as the rust side wrapper struct. (**footnote)

(**the long footnote) py-polars has 4 classes/structs from rust to python. DataFrame(rust-polars struct) -> PyDataFrame(wrapper struct) -> PyDataFrame (py03 internal class) -> DataFrame(py-polars public class). The vast majority of py-polars wrapper structs and wrapper classes are the thinnest possible. r-polars only has 3 classes/struct from rust to python: DataFrame(rust-polars struct) -> DataFrame(wrapper struct) -> DataFrame(extendr class). The R side DataFrame class though have both a set of public methods and a private method set. An early version of r-polars had 4 classes like py-polars and was using R6. That led to more conversions needed at runtime, more boiler plate code, and class instances was no longer just an R type ExternalPtr. Also, I felt it was sometimes cumbersome to make R6 behave exactly like py-polars syntax. Instead I decided to just implement extra base R S3 generic methods for the already auto-generated extendr-classes and add public method functions.

[vincentarelbundock]

FWIW, I agree that this is a useful change: I can imagine DataFrame vs. data.frame being confusing for some users.

I suggest to prefix all polars classes Polars, examples would be PolarsDataFrame PolarsSeries PolarsDataType

The names above seem fine. End-users will almost never need to write those out, so the length is almost irrelevant.

[etiennebacher]

To clarify, does this mean that

pl$DataFrame(a = 1:5, b = 1:5)

would change to

pl$PolarsDataFrame(a = 1:5, b = 1:5)

? Or that only the methods like ncol.DataFrame() are renamed to ncol.PolarsDataFrame()?

[sorhawell]

@etiennebacher hmm good question :/ I really just wanna have the cake and eat it to :)

long specfic class names, while short syntax. I hope it can make sense.

[eitsupi]

I feel that changes should be made to some of the following.

• Internal Rust lib polars -> r-polars (like py-polars https://github.com/pola-rs/polars/blob/5c61983dba25724ae0252eec3b46b877c0151a57/py-polars/Cargo.toml#L2)
• Rust struct names like DataFrame, to something like RDataFrame (like PyDataFrame https://github.com/pola-rs/polars/blob/5c61983dba25724ae0252eec3b46b877c0151a57/py-polars/src/dataframe.rs#L41)
• R class names like DataFrame, Series to something like PolarsDataFrame, PolarsSeries.

As for the function names in R, I think it makes sense to keep DataFrame, etc. since they are basically accessed by pl$.

[sorhawell]

Rust struct names like DataFrame, to something like RDataFrame (like PyDataFrame

I agree that is ideally best, but extendr does not currently support naming the R side and rust side differently. RDataFrame might look a bit strange on R side as the public class. On rust side it might not matter too much what the name is, just that it visually different from rust-polars class names e.g. DataFrame and Series. If we one day adopt S7 or extendr proc macros are updated, we can adopt RDataFrame and RSeries on rust side.

[eitsupi]

extendr does not currently support naming the R side and rust side differently.

It seems that extendr supports this. (r_name option)

#[extendr(
    r_name = "test.rename.rlike",
)]
fn test_rename() { }

https://github.com/extendr/extendr/blob/fc677380fa03c638e7913fdd96140da9ff1a5ad4/CHANGELOG.md?plain=1#L64-L75

Edit: I checked and found that r_name cannot actually be used to change the class name. I will try to update extendr.......

[eitsupi]

Related to extendr/extendr#553 and #253

[eitsupi]

Based on the discussion at #418, I think there is currently a consensus to adopt the prefix RPolars (e.g. RPolarsDataFrame).

[etiennebacher]

Where are we on this? #418 is closed so does that mean we can now rename all the classes RPolarsDataFrame, RPolarsExpr, etc. both on Rust and R sides?

[eitsupi]

Where are we on this? #418 is closed so does that mean we can now rename all the classes RPolarsDataFrame, RPolarsExpr, etc. both on Rust and R sides?

We simply need to rename the Rust structs here, since it seems unlikely that that functionality will be added to the extendr.