File 2461-Make-Module-init-1-mandatory.patch of Package erlang
From d30cae56d82763681b633cba25ad553eb672ec16 Mon Sep 17 00:00:00 2001
From: Raimo Niskanen <raimo@erlang.org>
Date: Thu, 6 Apr 2017 16:09:38 +0200
Subject: [PATCH 1/4] Make Module:init/1 mandatory
---
lib/stdlib/doc/src/gen_statem.xml | 17 ++++++++++-------
lib/stdlib/src/gen_statem.erl | 3 +--
2 files changed, 11 insertions(+), 9 deletions(-)
diff --git a/lib/stdlib/doc/src/gen_statem.xml b/lib/stdlib/doc/src/gen_statem.xml
index 5eb13db1a..f7baaad5d 100644
--- a/lib/stdlib/doc/src/gen_statem.xml
+++ b/lib/stdlib/doc/src/gen_statem.xml
@@ -146,7 +146,7 @@ erlang:'!' -----> Module:StateName/3
This gathers all code for a specific state
in one function as the <c>gen_statem</c> engine
branches depending on state name.
- Notice the fact that there is a mandatory callback function
+ Note the fact that the callback function
<seealso marker="#Module:terminate/3"><c>Module:terminate/3</c></seealso>
makes the state name <c>terminate</c> unusable in this mode.
</p>
@@ -1704,7 +1704,7 @@ handle_event(_, _, State, Data) ->
<func>
<name>Module:init(Args) -> Result(StateType)</name>
<fsummary>
- Optional function for initializing process and internal state.
+ Initializing process and internal state.
</fsummary>
<type>
<v>Args = term()</v>
@@ -1720,7 +1720,7 @@ handle_event(_, _, State, Data) ->
<seealso marker="#start_link/3"><c>start_link/3,4</c></seealso>
or
<seealso marker="#start/3"><c>start/3,4</c></seealso>,
- this optional function is called by the new process to initialize
+ this function is called by the new process to initialize
the implementation state and server data.
</p>
<p>
@@ -1729,13 +1729,16 @@ handle_event(_, _, State, Data) ->
</p>
<note>
<p>
- This callback is optional, so a callback module does not need
- to export it, but most do. If this function is not exported,
- the <c>gen_statem</c> should be started through
+ Note that if the <c>gen_statem</c> is started trough
<seealso marker="proc_lib"><c>proc_lib</c></seealso>
and
- <seealso marker="#enter_loop/4"><c>enter_loop/4-6</c></seealso>.
+ <seealso marker="#enter_loop/4"><c>enter_loop/4-6</c></seealso>,
+ this callback will never be called.
+ Since this callback is not optional it can
+ in that case be implemented as:
</p>
+ <pre>
+init(Args) -> erlang:error(not_implemented, [Args]).</pre>
</note>
</desc>
</func>
diff --git a/lib/stdlib/src/gen_statem.erl b/lib/stdlib/src/gen_statem.erl
index cacc932ec..242ff87be 100644
--- a/lib/stdlib/src/gen_statem.erl
+++ b/lib/stdlib/src/gen_statem.erl
@@ -287,8 +287,7 @@
StatusOption :: 'normal' | 'terminate'.
-optional_callbacks(
- [init/1, % One may use enter_loop/5,6,7 instead
- format_status/2, % Has got a default implementation
+ [format_status/2, % Has got a default implementation
terminate/3, % Has got a default implementation
code_change/4, % Only needed by advanced soft upgrade
%%
--
2.12.2
