rlang Important: The rlang API is still maturing. Please see ?rlang::lifecycle for the list of functions that are considered stable.OverviewThe 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 quosures (quo()).Consistent tools for working with base types. Note that overall this is a work in progress that is still in flux:Vectors, including construction (lgl(), int(), ...) coercion (as_logical(), as_character(), ...), and predicates (is_logical(), is_character()).Language objects, such as calls (lang()) and symbols (sym()).Attributes, e.g. set_names().Functions, e.g. new_function(), as_function(). The latter supports the purrr-style formula notation for lambda functions.Environments, e.g. env(), env_has(), env_get(), env_bind(), env_unbind().A comprehensive set of predicates to determine if an object satisfies various conditions, e.g. has_length(), is_list(), is_empty().The condition (message, warning, error) and restart system.InstallationYou can install the released version of rlang from CRAN with:install.packages("rlang")Or install the development version from github with:# install.packages("devtools") devtools::install_github("r-lib/rlang", build_vignettes = TRUE)