From 16f5e54b66615443b27653006fb68db43d32b57d Mon Sep 17 00:00:00 2001
From: Christophe De Troyer <christophe@call-cc.be>
Date: Mon, 23 Apr 2018 22:08:33 +0200
Subject: [PATCH] moves switch to seperate file

---
 lib/obs.ex                | 25 +------------------------
 lib/observables/switch.ex | 35 ++++++++++++++++++++++-------------
 test/observables_test.exs |  1 +
 3 files changed, 24 insertions(+), 37 deletions(-)

diff --git a/lib/obs.ex b/lib/obs.ex
index a8d52e5..685d057 100644
--- a/lib/obs.ex
+++ b/lib/obs.ex
@@ -158,31 +158,8 @@ defmodule Observables.Obs do
   end
 
   def switch({observable_fn, _parent_pid}) do
-    action = fn new_obs, s ->
-      switcher = self()
-
-      # Unsubscribe to the previous observer we were forwarding.
-      if s != nil do
-        {:forwarder, forwarder, :sender, observable} = s
-        {_f, pidf} = forwarder
-        GenObservable.stop_send_to(pidf, self())
-        {_f, pids} = observable
-        GenObservable.stop_send_to(pids, pidf)
-      end
-
-      # We subscribe to this observable.
-      # {_, obsvpid} = observable
-      # GenObservable.send_to(obsvpid, self())
-
-      forwarder =
-        new_obs
-        |> map(fn v -> GenObservable.send_event(switcher, {:forward, v}) end)
-
-      {:novalue, {:forwarder, forwarder, :sender, new_obs}}
-    end
-
     # Start the producer/consumer server.
-    {:ok, pid} = GenObservable.start_link(Switch, [action, nil])
+    {:ok, pid} = GenObservable.start_link(Switch, [])
 
     observable_fn.(pid)
 
diff --git a/lib/observables/switch.ex b/lib/observables/switch.ex
index 1280046..bedbc0e 100644
--- a/lib/observables/switch.ex
+++ b/lib/observables/switch.ex
@@ -3,29 +3,38 @@ defmodule Observables.Switch do
   A GenServer template for a "singleton" process.
   """
   use Observables.GenObservable
+  alias Observables.GenObservable
+  alias Observables.Obs
 
-  def init([action, state]) do
-    {:ok, %{:state => state, :action => action}}
+  def init([]) do
+    {:ok, nil}
   end
 
   def handle_event({:forward, v}, state) do
     {:value, v, state}
   end
 
-  def handle_event(e, %{:state => s, :action => a}) do
-    case a.(e, s) do
-      {:value, v, new_s} ->
-        {:value, v, %{:state => new_s, :action => a}}
+  def handle_event(new_obs, s) do
+    switcher = self()
 
-      {:novalue, new_s} ->
-        {:novalue, %{:state => new_s, :action => a}}
+    # Unsubscribe to the previous observer we were forwarding.
+    if s != nil do
+      {:forwarder, forwarder, :sender, observable} = s
+      {_f, pidf} = forwarder
+      GenObservable.stop_send_to(pidf, self())
+      {_f, pids} = observable
+      GenObservable.stop_send_to(pids, pidf)
+    end
 
-      {:done, new_s} ->
-        {:done, new_s}
+    # We subscribe to this observable.
+    # {_, obsvpid} = observable
+    # GenObservable.send_to(obsvpid, self())
 
-      _ ->
-        Logger.error("Invalid return value from Observable action!")
-    end
+    forwarder =
+      new_obs
+      |> Obs.map(fn v -> GenObservable.send_event(switcher, {:forward, v}) end)
+
+    {:novalue, {:forwarder, forwarder, :sender, new_obs}}
   end
 
   def handle_done(_pid, state) do
diff --git a/test/observables_test.exs b/test/observables_test.exs
index d24d072..6c8f287 100644
--- a/test/observables_test.exs
+++ b/test/observables_test.exs
@@ -215,6 +215,7 @@ defmodule ObservablesTest do
     end
   end
 
+  @tag :switch
   test "switch" do
     testproc = self()