Changelog

Source: NEWS.md

tarpolyglot 0.2.1

Bug fixes

• polyglot_controller() now fails gracefully when crew cannot build a controller on the host system, reporting what is wrong and what to do about it instead of passing the underlying error through. crew routes every controller through nanonext’s TLS layer: crew::crew_tls() validates by default, and that validation calls nanonext::tls_config() as a self-test whatever the TLS mode, so it runs even though this controller requests no TLS. Where nanonext was built without TLS support the self-test reports "Not supported" and no controller can be constructed, which is a property of the nanonext installation rather than of the arguments given.
• The crew tests skip on such a platform instead of failing, so R CMD check no longer errors there (seen on CRAN’s r-devel-linux-x86_64-fedora-clang). Two tests were added covering the new behaviour: that an unusable TLS layer produces the explanatory error, and that any other crew error is still passed through unchanged.

tarpolyglot 0.2.0

CRAN release: 2026-08-08

New features

• New dynamic-branching pattern helpers mirror the targets patterns (map(), cross(), slice(), …). Used unquoted in pattern on tar_target_rs() / tar_target_rs_raw(), they compile the Rust crate a single time in a companion <step name>_rust_lib target and reuse that compiled library across every branch (each branch reloads it in milliseconds), instead of recompiling the crate in every branch as the plain targets patterns do. On the other constructors (tar_target_py(), tar_target_jl(), or tar_target()) each helper falls back to its plain targets equivalent, so the same pattern code branches every language.
  • tarpolyglot_map(): equivalent to map()
  • tarpolyglot_cross(): equivalent to cross()
  • tarpolyglot_slice(): equivalent to slice()
  • tarpolyglot_head(): equivalent to head()
  • tarpolyglot_tail(): equivalent to tail()
  • tarpolyglot_sample(): equivalent to sample()

Bug fixes

• Inline Julia code supplied through tar_code() now runs correctly when it spans multiple top-level statements (for example a function definition followed by a call). It is evaluated as a Julia script rather than as a single expression, so it no longer raises ParseError("extra token after end of expression"). Inline Python and Rust were unaffected.

tarpolyglot 0.1.0

First release. tarpolyglot adds targets constructors that run Python, Julia, and Rust as pipeline steps.

New features

• tar_target_py(), tar_target_jl(), and tar_target_rs() (with matching _raw() variants) mirror targets::tar_target() / targets::tar_target_raw(). Python and Julia steps run a script through a live interpreter (reticulate / JuliaCall) with optional R pre- and post-scripts; Rust steps compile #[extendr] functions with rextendr and call them from an R post-script.
• Steps return either a converted R object or files written to disk (output = "file").
• tar_target_path() tracks a script file as a real targets dependency, so a step re-runs when its script changes.
• polyglot_controller() provides a crew controller preconfigured for per-step interpreter isolation (tasks_max = 1).
• Python environment selection via env / env_manager (system, virtualenv, venv, uv, poetry, conda), python_version, or an explicit python path; Julia selection via julia_version / julia_home / julia_project / julia_packages.
• Full targets::tar_target_raw() argument pass-through, including dynamic branching (pattern).
• tar_code() supplies inline code for the script, pre_script, and post_script arguments of the constructors, as an alternative to a file path or a tar_target_path() reference. An R {...} block is captured as inline R and is valid in the pre_script / post_script slots; a character string is inline source for the foreign script (Python, Julia, or Rust) or for an R pre/post-script. Multi-line strings are dedented, so code indented to line up with _targets.R still starts flush-left and Python’s own block indentation stays valid. Inline code is embedded in the target’s command, so targets hashes it and re-runs the step when it changes.