View Source erl_features (stdlib v6.2)
This module contains functions for supporting features that can be enabled/disabled in Erlang.
It should be considered as mostly for internal use, although there are some functions that might be useful when writing tools.
Summary
Functions
Return a list of all known features. This list will include features that have
been removed (status rejected) and features that are no longer configurable
(status permanent).
Return a list of all configurable features, that is, features with status
experimental or approved. These are the features that can be enabled or
disabled.
Return a list of the features that are currently enabled. Note that the set of enabled is set during startup and can then not be changed.
Return a map containing information about the given feature.
Return the list of features enabled when compiling the module. The module need not be loaded, but is found if it exists in the loadpath. If not all features used by the module are enabled in the runtime, loading the module is not allowed.
Types
-type feature() :: atom().
-type release() :: non_neg_integer().
-type status() :: experimental | approved | permanent | rejected.
-type type() :: extension | backwards_incompatible_change.
Functions
-spec all() -> [feature()].
Return a list of all known features. This list will include features that have
been removed (status rejected) and features that are no longer configurable
(status permanent).
-spec configurable() -> [feature()].
Return a list of all configurable features, that is, features with status
experimental or approved. These are the features that can be enabled or
disabled.
-spec enabled() -> [feature()].
Return a list of the features that are currently enabled. Note that the set of enabled is set during startup and can then not be changed.
-spec info(feature()) -> FeatureInfoMap | no_return() when Description :: string(), FeatureInfoMap :: #{description := Description, short := Description, type := type(), keywords := [atom()], status := status(), experimental => release(), approved => release(), permanent => release(), rejected => release()}.
Return a map containing information about the given feature.
-spec used(module() | file:filename()) -> [feature()].
Return the list of features enabled when compiling the module. The module need not be loaded, but is found if it exists in the loadpath. If not all features used by the module are enabled in the runtime, loading the module is not allowed.