env_poke()
will assign or reassign a binding in env
if create
is TRUE
. If create
is FALSE
and a binding does not already
exists, an error is issued.
env_poke(env = caller_env(), nm, value, inherit = FALSE, create = !inherit)
The old value of nm
or a zap sentinel if the
binding did not exist yet.
An environment.
Name of binding, a string.
The value for a new binding.
Whether to look for bindings in the parent environments.
Whether to create a binding if it does not already exist in the environment.
If inherit
is TRUE
, the parents environments are checked for
an existing binding to reassign. If not found and create
is
TRUE
, a new binding is created in env
. The default value for
create
is a function of inherit
: FALSE
when inheriting,
TRUE
otherwise.
This default makes sense because the inheriting case is mostly
for overriding an existing binding. If not found, something
probably went wrong and it is safer to issue an error. Note that
this is different to the base R operator <<-
which will create
a binding in the global environment instead of the current
environment when no existing binding is found in the parents.
env_bind()
for binding multiple elements. env_cache()
for a variant of env_poke()
designed to cache values.