Update Gen_FSM example to be more explicit, clear.

By using a locally registered process name, this example has caused some
initial confusion to new users of Elixir. Using explicit PIDs will more
closely align with other examples, and reduce the number of things one
must understand in order to understand this example.

Author: bitwalker

lib/elixir/lib/gen_fsm/behaviour.ex

@@ -31,15 +31,15 @@ defmodule GenFSM.Behaviour do
         # API functions
 
         def start_link() do
-          :gen_fsm.start_link({:local, :cvm}, __MODULE__, [], [])
+          :gen_fsm.start_link(__MODULE__, [], [])
         end
 
-        def insert_coin() do
-          :gen_fsm.send_event(:cvm, :coin)
+        def insert_coin(pid) do
+          :gen_fsm.send_event(pid, :coin)
         end
 
-        def request_coffee() do
-          :gen_fsm.send_event(:cvm, :request_coffee)
+        def request_coffee(pid) do
+          :gen_fsm.send_event(pid, :request_coffee)
         end
 
         # Callbacks
@@ -83,17 +83,17 @@ defmodule GenFSM.Behaviour do
         end
       end
 
-      { :ok, _pid } = MyFsm.start_link()
+      { :ok, pid } = MyFsm.start_link()
 
-      MyFsm.insert_coin
+      MyFsm.insert_coin(pid)
       #=> :ok
-      MyFsm.insert_coin
+      MyFsm.insert_coin(pid)
       #=> :ok
 
-      MyFsm.request_coffee
+      MyFsm.request_coffee(pid)
       #=> :ok
 
-      MyFsm.insert_coin
+      MyFsm.insert_coin(pid)
       #=> :ok
       #=> Here's your coffee!