Merge branch 'raimo/new-gen-state-machine/OTP-13065'

* raimo/new-gen-state-machine/OTP-13065: (52 commits)
  Add section on state filtering
  Promote gen_statem over gen_fsm
  Modify code_change/4 to return CallbackMode
  Use ?NAME macro in examples
  Introduce Fred Herbert suggested additions
  Introduce corrections from Fred Hebert and Ingela
  Use .png pictures instead of .gif
  Write Design Principles chapter
  Fix missing short forms for event timeout
  Do more intricate Fred Hebert doc changes
  Change Caller -> From as suggested by Fred Hebert
  Do documentation improvements from Fred Hebert
  Fix broken documenation reference
  Rename state_timeout -> event_timeout
  Fix most of the system docs and emacs mode
  Change code_change/4 to {ok,State,Data}
  Fixup sharpened test suite
  Sharpen test suite
  Remove the remove_event action and all alike
  Relax caller() type check and cleanup
  ...

Conflicts:
	lib/stdlib/src/gen.erl
	lib/stdlib/src/gen_event.erl
	lib/stdlib/src/gen_fsm.erl
	lib/stdlib/src/gen_server.erl
	lib/stdlib/test/error_logger_forwarder.erl

1 files changed, 13 insertions, 1 deletions

diff --git a/lib/stdlib/doc/src/gen_fsm.xml b/lib/stdlib/doc/src/gen_fsm.xml
index 37e7c6ed17..835e252704 100644
--- a/lib/stdlib/doc/src/gen_fsm.xml
+++ b/lib/stdlib/doc/src/gen_fsm.xml
@@ -31,12 +31,23 @@
   <module>gen_fsm</module>
   <modulesummary>Generic Finite State Machine Behaviour</modulesummary>
   <description>
+    <note>
+      <p>
+	There is a new behaviour
+	<seealso marker="gen_statem"><c>gen_statem</c></seealso>
+	that is intended to replace <c>gen_fsm</c> for new code.
+	It has the same features and add some really useful.
+	This module will not be removed for the foreseeable future
+	to keep old state machine implementations running.
+      </p>
+    </note>
     <p>A behaviour module for implementing a finite state machine.
       A generic finite state machine process (gen_fsm) implemented
       using this module will have a standard set of interface functions
       and include functionality for tracing and error reporting. It will
       also fit into an OTP supervision tree. Refer to
-      <seealso marker="doc/design_principles:fsm">OTP Design Principles</seealso> for more information.</p>
+      <seealso marker="doc/design_principles:fsm">OTP Design Principles</seealso> for more information.
+    </p>
     <p>A gen_fsm assumes all specific parts to be located in a callback
       module exporting a pre-defined set of functions. The relationship
       between the behaviour functions and the callback functions can be
@@ -848,6 +859,7 @@ gen_fsm:sync_send_all_state_event -----> Module:handle_sync_event/4
     <title>SEE ALSO</title>
     <p><seealso marker="gen_event">gen_event(3)</seealso>,
       <seealso marker="gen_server">gen_server(3)</seealso>,
+      <seealso marker="gen_statem">gen_statem(3)</seealso>,
       <seealso marker="supervisor">supervisor(3)</seealso>,
       <seealso marker="proc_lib">proc_lib(3)</seealso>,
       <seealso marker="sys">sys(3)</seealso></p>