Life cycle of the rlang package

The rlang package is currently maturing. Unless otherwise stated, this applies to all its exported functions. Maturing functions are susceptible to API changes. Only use these in packages if you're prepared to make changes as the package evolves. See sections below for a list of functions marked as stable.

The documentation pages of retired functions contain life cycle sections that explain the reasons for their retirements.

Stable functions

• eval_tidy()

• !!, !!!

• enquo(), quo(), quos()

• enexpr(), expr(), exprs()

• sym(), syms()

• new_quosure(), is_quosure()

• missing_arg(), is_missing()

• quo_get_expr(), quo_set_expr()

• quo_get_env(), quo_set_env()

• eval_bare()

• set_names(), names2()

• as_function(), new_function()

Experimental functions

These functions are not yet part of the rlang API. Expect breaking changes.

• with_env(), locally(), env_poke()

• pkg_env(), pkg_env_name(), ns_env(), ns_imports_env(), ns_env_name()

• is_pairlist(), as_pairlist(), is_node(), is_node_list()

• is_definition(), new_definition(), is_formulaish(), dots_definitions()

• local_options(), with_options(), push_options(), peek_options(), peek_option()

• as_bytes(), chr_unserialise_unicode()

• caller_fn(), current_fn()

Questioning stage

In the questioning stage as of rlang 0.4.0

These functions are likely to be moved to the vctrs package:

• lgl(), int(), etc.

• new_logical(), new_integer(), etc.

• na_lgl, na_int, is_lgl_na(), is_int_na(), etc.

In the questioning stage as of rlang 0.3.0

• child_env()

• flatten(), squash(), and their atomic vector variants

• modify() and prepend()

• with_restarts(), rst_list(), rst_exists(), rst_jump(), rst_maybe_jump(), rst_abort(). It is not clear yet whether we want to recommend restarts as a style of programming in R.

• return_from() and return_to().

• expr_label(), expr_name(), and expr_text().

In the questioning stage as of rlang 0.2.0

• UQ(), UQS()

• dots_splice(), splice()

Soft-deprecated functions and arguments

Soft-deprecated in rlang 0.4.0

• exiting(): Handlers are now treated as exiting by default.

• invoke(): Use the simpler exec() instead.

• as_logical(), as_integer(), etc. => vctrs::vec_cast().

• type_of(), switch_type(), coerce_type(), switch_class(), coerce_class()

Deprecated functions and arguments

Bumped to deprecated in rlang 0.4.0

• modify() and prepend().

• new_logical_along(), new_integer_along(), new_double_along(), new_complex_along(), new_character_along(), new_raw_along(), new_list_along().

• lang_modify() => call_modify()

• lang_standardise() => call_standardise()

• lang_fn() => call_fn()

• lang_name() => call_name()

• lang_args() => call_args()

• lang_args_names() => call_args_names()

• lang_head(), lang_tail()

• lang() => call2()

• new_language() => new_call()

• is_lang() => is_call()

• is_unary_lang() => Use the n argument of is_call()

• is_binary_lang() => Use the n argument of is_call()

• quo_is_lang() => quo_is_call()

• call_modify(): .standardise and .env arguments.

• is_expr() => is_expression()

• quo_expr() => quo_squash()

• parse_quosure() => parse_quo()

• parse_quosures() => parse_quos()

• Assigning non-quosure objects to quosure lists.

• as.character() on quosures.

• cnd_signal(): .cnd => cnd

• cnd_signal(): The .mufflable argument no longer has any effect

• scoped_names() => base::search()

• is_scoped() => is_attached()

• scoped_env() => search_env()

• scoped_envs() => search_envs()

• env_bind_exprs() => env_bind_lazy()

• env_bind_fns() => env_bind_active()

• Passing a function or formula to env_depth(), env_poke_parent(), env_parent<-, env_tail(), set_env(), env_clone(), env_inherits(), env_bind(), local_bindings(), with_bindings(), env_poke(), env_has(), env_get(), env_names(), env_bind_exprs() and env_bind_fns(). This internal genericity was causing confusion (see issue #427). You should now extract the environment separately before calling these functions.

• get_env(): The env argument no longer has a default and must be supplied

• is_frame(), global_frame(), current_frame(), ctxt_frame(), call_frame(), frame_position(), caller_frame()

• ctxt_depth(), call_depth(), ctxt_stack(), call_stack(), stack_trim()

• set_attrs(), mut_attrs()

• The width and printer arguments of exprs_auto_name() and quos_auto_name() no longer have any effect. For the same reason, passing a width as .named argument of dots collectors like quos() is deprecated.

• as_overscope() => as_data_mask()

• new_overscope() => new_data_mask()

• overscope_eval_next() => eval_tidy()

• overscope_clean()

Defunct functions and arguments

Defunct as of rlang 0.4.0

• length() and names() on tidy eval .data pronouns.

• Supplying a named !!! call.