rlang

Low-level API for programming with R

rlang is a collection of frameworks and APIs for programming with R. It provides tools for building functions, working with R objects, and creating better error messages.

The package includes two major frameworks: tidy eval for data-masking (used in dplyr and ggplot2) and rlang errors for improved error signaling and backtraces. It offers utilities for argument validation, working with environments and functions, and metaprogramming tasks like manipulating calls and symbols. These tools help package developers write more robust code and provide better user experiences through structured error handling and flexible argument processing.