rlang: env_get – R documentation

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env_get

Get an object in an environment

Description

env_get() extracts an object from an enviroment env. By default, it does not look in the parent environments. env_get_list() extracts multiple objects from an environment into a named list.

Usage

env_get(env = caller_env(), nm, default, inherit = FALSE)

env_get_list(env = caller_env(), nms, default, inherit = FALSE)

Arguments

`env`	An environment.
`nm, nms`	Names of bindings. `nm` must be a single string.
`default`	A default value in case there is no binding for `nm` in `env`.
`inherit`	Whether to look for bindings in the parent environments.

Value

An object if it exists. Otherwise, throws an error.

Examples

parent <- child_env(NULL, foo = "foo")
env <- child_env(parent, bar = "bar")

# This throws an error because `foo` is not directly defined in env:
# env_get(env, "foo")

# However `foo` can be fetched in the parent environment:
env_get(env, "foo", inherit = TRUE)

# You can also avoid an error by supplying a default value:
env_get(env, "foo", default = "FOO")

rlang

Functions for Base Types and Core R and 'Tidyverse' Features

v0.4.11

MIT + file LICENSE

Authors

Lionel Henry [aut, cre], Hadley Wickham [aut], mikefc [cph] (Hash implementation based on Mike's xxhashlite), Yann Collet [cph] (Author of the embedded xxHash library), RStudio [cph]

Initial release