File 2571-fix-some-errors-in-code-samples-for-gen_statem-behav.patch of Package erlang
From 2ad6bce714cf1f6ced42969a7dbd9e5cd6979a4b Mon Sep 17 00:00:00 2001
From: Alberto Sartori <alberto.sartori.as@gmail.com>
Date: Tue, 3 Jul 2018 10:47:24 +0200
Subject: [PATCH] fix some errors in code samples for gen_statem behaviour
* consistently use var name `Button` instead of `Digit`
* remove unnecessary calls to `do_lock` and `do_unlock`
* fix compile errors
---
system/doc/design_principles/statem.xml | 47 +++++++++++++++------------------
1 file changed, 22 insertions(+), 25 deletions(-)
diff --git a/system/doc/design_principles/statem.xml b/system/doc/design_principles/statem.xml
index 80ee9c992f..16a901b3a5 100644
--- a/system/doc/design_principles/statem.xml
+++ b/system/doc/design_principles/statem.xml
@@ -956,14 +956,14 @@ callback_mode() ->
<seealso marker="stdlib:gen_statem#cast/2"><c>gen_statem:cast/2</c></seealso>:
</p>
<code type="erl"><![CDATA[
-button(Digit) ->
- gen_statem:cast(?NAME, {button,Digit}).
+button(Button) ->
+ gen_statem:cast(?NAME, {button,Button}).
]]></code>
<p>
The first argument is the name of the <c>gen_statem</c> and must
agree with the name used to start it. So, we use the
same macro <c>?NAME</c> as when starting.
- <c>{button,Digit}</c> is the event content.
+ <c>{button,Button}</c> is the event content.
</p>
<p>
The event is sent to the <c>gen_statem</c>.
@@ -1171,7 +1171,7 @@ open(...) -> ... ;
callback_mode() ->
handle_event_function.
-handle_event(cast, {button,Digit}, State, #{code := Code} = Data) ->
+handle_event(cast, {button,Button}, State, #{code := Code} = Data) ->
case State of
locked ->
#{length := Length, buttons := Buttons} = Data,
@@ -1305,7 +1305,7 @@ stop() ->
locked(timeout, _, Data) ->
{next_state, locked, Data#{buttons := []}};
locked(
- cast, {button,Digit},
+ cast, {button,Button},
#{code := Code, length := Length, buttons := Buttons} = Data) ->
...
true -> % Incomplete | Incorrect
@@ -1364,7 +1364,7 @@ locked(
<code type="erl"><![CDATA[
...
locked(
- cast, {button,Digit},
+ cast, {button,Button},
#{code := Code, length := Length, buttons := Buttons} = Data) ->
...
if
@@ -1421,7 +1421,7 @@ open(cast, {button,_}, Data) ->
<code type="erl"><![CDATA[
...
locked(
- cast, {button,Digit},
+ cast, {button,Button},
#{code := Code, length := Length, buttons := Buttons} = Data) ->
...
if
@@ -1662,7 +1662,7 @@ locked(enter, _OldState, Data) ->
do_lock(),
{keep_state,Data#{buttons => []}};
locked(
- cast, {button,Digit},
+ cast, {button,Button},
#{code := Code, length := Length, buttons := Buttons} = Data) ->
...
if
@@ -1747,7 +1747,7 @@ open(state_timeout, lock, Data) ->
</p>
<code type="erl"><![CDATA[
...
--export(down/1, up/1).
+-export([down/1, up/1]).
...
down(Button) ->
gen_statem:cast(?NAME, {down,Button}).
@@ -1759,15 +1759,15 @@ up(Button) ->
locked(enter, _OldState, Data) ->
do_lock(),
- {keep_state,Data#{remaining => Code, buf => []}};
+ {keep_state,Data#{buttons => []}};
locked(
- internal, {button,Digit},
+ internal, {button,Button},
#{code := Code, length := Length, buttons := Buttons} = Data) ->
...
]]></code>
<code type="erl"><![CDATA[
handle_common(cast, {down,Button}, Data) ->
- {keep_state, Data#{button := Button}};
+ {keep_state, Data#{button => Button}};
handle_common(cast, {up,Button}, Data) ->
case Data of
#{button := Button} ->
@@ -1833,10 +1833,10 @@ start_link(Code) ->
stop() ->
gen_statem:stop(?NAME).
-down(Digit) ->
- gen_statem:cast(?NAME, {down,Digit}).
-up(Digit) ->
- gen_statem:cast(?NAME, {up,Digit}).
+down(Button) ->
+ gen_statem:cast(?NAME, {down,Button}).
+up(Button) ->
+ gen_statem:cast(?NAME, {up,Button}).
code_length() ->
gen_statem:call(?NAME, code_length).
]]></code>
@@ -1873,7 +1873,7 @@ locked(enter, _OldState, Data) ->
locked(state_timeout, button, Data) ->
{keep_state, Data#{buttons := []}};
locked(
- internal, {button,Digit},
+ internal, {button,Button},
#{code := Code, length := Length, buttons := Buttons} = Data) ->
NewButtons =
if
@@ -1884,7 +1884,6 @@ locked(
end ++ [Button],
if
NewButtons =:= Code -> % Correct
- do_unlock(),
{next_state, open, Data};
true -> % Incomplete | Incorrect
{keep_state, Data#{buttons := NewButtons},
@@ -1940,7 +1939,7 @@ handle_event(enter, _OldState, locked, Data) ->
handle_event(state_timeout, button, locked, Data) ->
{keep_state, Data#{buttons := []}};
handle_event(
- internal, {button,Digit}, locked,
+ internal, {button,Button}, locked,
#{code := Code, length := Length, buttons := Buttons} = Data) ->
NewButtons =
if
@@ -1951,7 +1950,6 @@ handle_event(
end ++ [Button],
if
NewButtons =:= Code -> % Correct
- do_unlock(),
{next_state, open, Data};
true -> % Incomplete | Incorrect
{keep_state, Data#{buttons := NewButtons},
@@ -2152,7 +2150,7 @@ handle_event(enter, _OldState, {locked,_}, Data) ->
handle_event(state_timeout, button, {locked,_}, Data) ->
{keep_state, Data#{buttons := []}};
handle_event(
- cast, {button,Digit}, {locked,LockButton},
+ cast, {button,Button}, {locked,LockButton},
#{code := Code, length := Length, buttons := Buttons} = Data) ->
NewButtons =
if
@@ -2163,7 +2161,6 @@ handle_event(
end ++ [Button],
if
NewButtons =:= Code -> % Correct
- do_unlock(),
{next_state, {open,LockButton}, Data};
true -> % Incomplete | Incorrect
{keep_state, Data#{buttons := NewButtons},
@@ -2177,11 +2174,11 @@ handle_event(enter, _OldState, {open,_}, _Data) ->
do_unlock(),
{keep_state_and_data,
[{state_timeout,10000,lock}]}; % Time in milliseconds
-handle_event(state_timeout, lock, {open,_}, Data) ->
- {next_state, locked, Data};
+handle_event(state_timeout, lock, {open,LockButton}, Data) ->
+ {next_state, {locked,LockButton}, Data};
handle_event(cast, {button,LockButton}, {open,LockButton}, Data) ->
{next_state, {locked,LockButton}, Data};
-handle_event(cast, {button,_}, {open,_}, Data) ->
+handle_event(cast, {button,_}, {open,_}, _Data) ->
{keep_state_and_data,[postpone]};
]]></code>
<code type="erl"><
