Share Zig modules between R packages — use_rzig

A package can share Zig code with other packages as a Zig module: the file inst/zig/<module>/root.zig, with the files it imports from that folder, installed with the package. use_rzig_import() lets the Zig code of the package at path use such a module with @import("<module>"): it adds <package>/<module> to the field Config/rzig/imports of DESCRIPTION and <package> to LinkingTo, so that R installs the providing package first. configure finds the module in the installed package and passes it to zig build; the module can import rzig and the other imported modules. The module is compiled into the importing package, so nothing is linked between the packages when they run.

Usage

use_rzig_import(path, package, module)

use_rzig_module(path, module, import = TRUE)

Arguments

path: Path to the package root.
package: The name of the package that provides the module.
module: The name of the Zig module, a Zig identifier other than rzig, std, builtin and root.
import: For use_rzig_module(): also import the module in the package's own Zig code.

Value

The path of DESCRIPTION (use_rzig_import()) or of the module's root.zig (use_rzig_module()), invisibly.

Details

use_rzig_module() creates inst/zig/<module>/root.zig with a starter in the providing package and, with import = TRUE, imports the module in the package's own Zig code as well (an entry that names the package itself refers to its source). It also writes inst/include/<package>_rzig.h, a header without declarations: R CMD check expects a package in LinkingTo to provide an include directory.

Examples

provider <- tempfile("rzig-provider-", tmpdir = tempdir())
dir.create(provider)
writeLines(c("Package: kernelpkg", "Version: 0.0.1"), file.path(provider, "DESCRIPTION"))
use_rzig_module(provider, "kernels")
#> Package kernelpkg provides the Zig module kernels in inst/zig/kernels/root.zig
consumer <- tempfile("rzig-consumer-", tmpdir = tempdir())
dir.create(consumer)
writeLines(c("Package: userpkg", "Version: 0.0.1"), file.path(consumer, "DESCRIPTION"))
use_rzig_import(consumer, "kernelpkg", "kernels")
#> Package userpkg imports the Zig module kernels of package kernelpkg
read.dcf(file.path(consumer, "DESCRIPTION"), fields = c("LinkingTo", "Config/rzig/imports"))
#>      LinkingTo   Config/rzig/imports
#> [1,] "kernelpkg" "kernelpkg/kernels"
unlink(c(provider, consumer), recursive = TRUE)