r-conventions

- R 4.1+, a consistent style guide (e.g., tidyverse), a formatter (e.g., styler) and a linter (e.g., lintr). - Base R pipe `|>` over magrittr `%>%`, prefer base R when tidyverse not needed. - Package dev: `devtools`/`usethis`/`roxygen2`, `testthat` (80%+ via a coverage tool, e.g., covr). - Documentation: roxygen2 for inline docs and NAMESPACE management. `@examples` on all exports. - Vignettes with `knitr`/`rmarkdown` for long-form documentation and tutorials. - Error handling: `tryCatch()`/`withCallingHandlers()`, `cli::cli_abort()` for user-facing errors. - Input validation: `checkmate` or `rlang::arg_match()` for function parameter validation. - Security: a dependency vulnerability scanner (e.g., oysteR). - C/C++: `Rcpp` or `.Call()`, PROTECT/UNPROTECT all R objects. Rust: `extendr`/`rextendr`. - CRAN: `R CMD check --as-cran` zero warnings/notes, maintain DESCRIPTION with proper versioning. - Anti-patterns: `eval(parse(text=))` with user input, mixing Rcpp and raw C API, `T`/`F` instead of `TRUE`/`FALSE`.