Rapp

Rapp is a drop-in replacement for Rscript that automatically parses command-line arguments into R values, making it straightforward to build polished CLI applications from simple R scripts. It converts standard R patterns like scalar assignments, NULL assignments, and switch statements into command-line options, positional arguments, and commands without requiring explicit argument parsing libraries.

The package enables seamless transition from interactive REPL development to command-line execution by recognizing R expression patterns at the top level of scripts. It handles option parsing, type coercion, automatic help generation, nested commands with their own options, and repeatable arguments through familiar R syntax. Rapp works cross-platform including Windows, supports distribution via R packages through the exec/ directory, and allows interactive development with Rapp::run() for debugging.