Dynamic-branching cross that compiles Rust once

A drop-in replacement for the targets targets::tar_target() pattern helper cross(), for use unquoted in the pattern argument of a tarpolyglot constructor. Like tarpolyglot_map(), on tar_target_rs() it compiles the extendr crate once in a companion <name>_rust_lib target and reuses it across every branch (instead of recompiling per branch); on tar_target_py() / tar_target_jl() it is exactly cross(). See tarpolyglot_map() for the full explanation and the compile-once mechanics.

Usage

tarpolyglot_cross(...)

Arguments

...

Upstream targets to cross (all combinations), with the same meaning as in the targets cross() pattern.

Value

This function is a marker consumed by the tarpolyglot constructors and is not meant to be evaluated on its own; calling it directly raises an error.

See also

tarpolyglot_map(), tar_target_rs(), tar_target_py(), tar_target_jl()

Examples

if (FALSE) { # \dontrun{
tarpolyglot::tar_target_rs(
  name = rs_grid, script = "square.rs", inputs = c(x = "a", y = "b"),
  post_script = "post.R", pattern = tarpolyglot_cross(a, b)
)
} # }