Locked environments cannot be modified. An important example is namespace environments which are locked by R when loaded in a session. Once an environment is locked it normally cannot be unlocked.

Note that only the environment as a container is locked, not the individual bindings. You can't remove or add a binding but you can still modify the values of existing bindings. See env_binding_lock() for locking individual bindings.

env_lock(env)

env_is_locked(env)

## Arguments

env An environment.

## Value

The old value of env_is_locked() invisibly.

env_binding_lock()

## Examples

# New environments are unlocked by default:
env <- env(a = 1)
env_is_locked(env)#> [1] FALSE
# Use env_lock() to lock them:
env_lock(env)
env_is_locked(env)#> [1] TRUE
# Now that env is locked, it is no longer possible to remove or
# add bindings. If run, the following would fail:
# env_unbind(env, "a")
# env_bind(env, b = 2)

# Note that even though the environment as a container is locked,
# the individual bindings are still unlocked and can be modified:
env\$a <- 10