Important: The rlang API is still maturing. Please see ?rlang::lifecycle for the list of functions that are considered stable.
The rlang package provides tools to work with core language features of R and the tidyverse:
The tidy eval framework, which is a well-founded system for non-standard evaluation built on quasiquotation (!!) and quoted arguments (enquo()). See https://tidyeval.tidyverse.org.
User-friendly error reporting with backtraces and chained errors (abort(), trace_back(), with_abort()).
A consistent API for working with base types. Note that overall this is a work in progress that is still in flux:
Environments, e.g. env(), env_has(), env_get(), env_bind(), env_unbind(), env_print().
Calls and symbols, e.g. call2(), is_call(), sym(), syms().
Functions, e.g. new_function(), as_function(). The latter supports the purrr-style formula notation for lambda functions.
Vectors, including construction (lgl(), int(), …) and predicates (is_logical(), is_character()).
Attributes, e.g. set_names().
You can install the released version of rlang from CRAN with:
Or install the development version from github with:
