Export tiledb_datatype_R_type

[eddelbuettel]

This is a bit of a micro-PR to benefit @LTLA and BioConductor package TileDBArray which currently accesses a C++-level function tiledb_datatype_R_type mapping from TileDB type (as string) to R type (as string) via ::: as the function is not exported.

This PR corrects this and exports the function.

[shortcut-integration]

This pull request has been linked to Shortcut Story #12830: Export helper type mapping function used by BioConductor's TileDBArray.

[ihnorton]

I believe the mapping here is stable and (effectively) covered by existing tests, since we use this function internally, right?

[eddelbuettel]

Yes it should be and the package itself does not use it outside of code disappearing with the to-be-deprecated-in-draft-PR-#335:

edd@rob:~/git/tiledb-r(feature/sc-12830/export_datatype_mapper)$ ag tiledb_datatype_R_type R/
R/SparseArray.R
116:    type <- tiledb_datatype_R_type(dtype)

R/DenseArray.R
231:    type <- tiledb_datatype_R_type(dtype)

R/RcppExports.R
51:tiledb_datatype_R_type <- function(datatype) {
52:    .Call(`_tiledb_tiledb_datatype_R_type`, datatype)
edd@rob:~/git/tiledb-r(feature/sc-12830/export_datatype_mapper)$ 

So it really is just a courtesy export for external functionality shadowing what we used to do / still do (technically) til the deprecated code is lifted. But it does no harm and is, as you say, type-stable.