cleanup and clarify provider spec

1 files changed, 12 insertions, 4 deletions

diff --git a/src/rcl_provider.erl b/src/rcl_provider.erl
index 5c73075..5aa10bd 100644
--- a/src/rcl_provider.erl
+++ b/src/rcl_provider.erl
@@ -8,7 +8,7 @@
 -module(rcl_provider).
 
 %% API
--export([new/2, do/2, format/1]).
+-export([new/2, do/2, format_error/2, format/1]).
 
 -export_type([t/0]).
 
@@ -20,7 +20,7 @@
 
 -callback init(rcl_state:t()) -> {ok, rcl_state:t()} | {error, Reason::term()}.
 -callback do(rcl_state:t()) -> {error, Reason::term()} | {ok, rcl_state:t()}.
--callback format({error, Reason::term()}) -> iolist().
+-callback format_error({error, Reason::term()}) -> iolist().
 
 %%%===================================================================
 %%% API
@@ -31,7 +31,8 @@
 %%
 %% @param ModuleName The module name.
 %% @param State0 The current state of the system
--spec new(module(), rcl_state:t()) -> {t(), {ok, rcl_state:t()} | {error, Reason::term()}}.
+-spec new(module(), rcl_state:t()) ->
+                 {t(), {ok, rcl_state:t()} | {error, Reason::term()}}.
 new(ModuleName, State0) when is_atom(ModuleName) ->
     State1 = ModuleName:init(State0),
     case code:which(ModuleName) of
@@ -46,10 +47,17 @@ new(ModuleName, State0) when is_atom(ModuleName) ->
 %%
 %% @param Provider the provider object
 %% @param State the current state of the system
--spec do(Provider::t(), rcl_state:t()) -> rcl_state:t().
+-spec do(Provider::t(), rcl_state:t()) ->
+                {error, Reason::term()} | {ok, rcl_state:t()}.
 do({?MODULE, Mod}, State) ->
     Mod:do(State).
 
+%% @doc format an error produced from a provider.
+-spec format_error(t(), {error, Reason::term()}) -> iolist().
+format_error({?MODULE, Mod}, Error) ->
+    Mod:format_error(Error).
+
+
 %% @doc print the provider module name
 %%
 %% @param T - The provider