From 3a60545091d3075e23c4a7af8c18b3641bb084e2 Mon Sep 17 00:00:00 2001 From: Raimo Niskanen Date: Tue, 9 Aug 2016 08:59:51 +0200 Subject: Doc fixes --- lib/stdlib/doc/src/gen_statem.xml | 56 ++++++++++++++------------------------- 1 file changed, 20 insertions(+), 36 deletions(-) (limited to 'lib/stdlib/doc') diff --git a/lib/stdlib/doc/src/gen_statem.xml b/lib/stdlib/doc/src/gen_statem.xml index f18c1087ab..3322571b2c 100644 --- a/lib/stdlib/doc/src/gen_statem.xml +++ b/lib/stdlib/doc/src/gen_statem.xml @@ -119,9 +119,11 @@ erlang:'!' -----> Module:StateName/3

If a callback function fails or returns a bad value, - the gen_statem terminates. However, an exception of class + the gen_statem terminates, unless otherwise stated. + However, an exception of class throw - is not regarded as an error but as a valid return. + is not regarded as an error but as a valid return + from all callback functions.

@@ -917,7 +919,8 @@ handle_event(_, _, State, Data) ->

- To avoid getting a late reply in the caller's + For Timeout =/= infinity, + to avoid getting a late reply in the caller's inbox, this function spawns a proxy process that does the call. A late reply gets delivered to the dead proxy process, hence gets discarded. This is @@ -1288,12 +1291,6 @@ handle_event(_, _, State, Data) -> Module:code_change/4 returns.

-

- This function can use - erlang:throw/1 - to return CallbackMode, just for symmetry reasons. - There should be no actual reason to use this. -

If this function's body does not consist of solely one of two @@ -1368,11 +1365,6 @@ handle_event(_, _, State, Data) -> It is recommended to use an atom as Reason since it will be wrapped in an {error,Reason} tuple.

-

- This function can use - erlang:throw/1 - to return Result or Reason. -

@@ -1432,11 +1424,6 @@ handle_event(_, _, State, Data) -> or ignore; see start_link/3,4.

-

- This function can use - erlang:throw/1 - to return Result. -

This callback is optional, so a callback module does not need @@ -1477,10 +1464,14 @@ handle_event(_, _, State, Data) -> This callback is optional, so a callback module does not need to export it. The gen_statem module provides a default implementation of this function that returns - {State,Data}. If this callback fails, the default - function returns {State,Info}, - where Info informs of the crash but no details, - to hide possibly sensitive data. + {State,Data}. +

+

+ If this callback is exported but fails, + to hide possibly sensitive data, + the default function will instead return {State,Info}, + where Info says nothing but the fact that + format_status/2 has crashed.

This function is called by a gen_statem process when @@ -1541,11 +1532,6 @@ handle_event(_, _, State, Data) -> printed in log files. Another use is to hide sensitive data from being written to the error log.

-

- This function can use - erlang:throw/1 - to return Status. -

@@ -1620,9 +1606,12 @@ handle_event(_, _, State, Data) -> see action().

- These functions can use - erlang:throw/1, - to return the result. + Note the fact that you can use + throw + to return the result, which can be useful. + For example to bail out with throw(keep_state_and_data) + from deep within complex code that is in no position to + return {next_state,State,Data}.

@@ -1695,11 +1684,6 @@ handle_event(_, _, State, Data) -> and an error report is issued using error_logger:format/2.

-

- This function can use - erlang:throw/1 - to return Ignored, which is ignored anyway. -

-- cgit v1.2.3