From d5bd79f114655bc7f416bd3ae2c90510b58c9c0b Mon Sep 17 00:00:00 2001
From: Juan Facorro <juan.facorro@gmail.com>
Date: Wed, 10 Jun 2015 01:59:24 -0300
Subject: [PATCH] [#12] Encode protocol implementation for Any, but actually
 only for structs

---
 lib/ex_edn/encode.ex | 10 ++++++++++
 test/ex_edn_test.exs |  6 ++++++
 2 files changed, 16 insertions(+)

diff --git a/lib/ex_edn/encode.ex b/lib/ex_edn/encode.ex
index 1361423..a3b8fca 100644
--- a/lib/ex_edn/encode.ex
+++ b/lib/ex_edn/encode.ex
@@ -6,6 +6,7 @@ alias ExEdn.UUID
 alias ExEdn.Tag
 
 defprotocol ExEdn.Encode do
+  @fallback_to_any true
   def encode(value)
 end
 
@@ -101,3 +102,12 @@ defimpl Encode, for: Timex.DateTime do
     Encode.encode(Tag.new("inst", value))
   end
 end
+
+defimpl Encode, for: Any do
+  def encode(struct) when is_map(struct) do
+    Encode.encode(Map.from_struct(struct))
+  end
+  def encode(_)  do
+    raise Protocol.UndefinedError
+  end
+end
diff --git a/test/ex_edn_test.exs b/test/ex_edn_test.exs
index b3fc834..25180d7 100644
--- a/test/ex_edn_test.exs
+++ b/test/ex_edn_test.exs
@@ -132,6 +132,12 @@ defmodule ExEdnTest do
     assert encode!(some_tag) == "#custom/tag :joni"
   end
 
+  test "Encode Fallback to Any" do
+    node = %ExEdn.Parser.Node{}
+    map = Map.from_struct(node)
+    assert encode!(node) == encode!(map)
+  end
+
   test "Encode Unknown Type" do
     e = %Protocol.UndefinedError{}
     assert encode(self) == {:error, e.__struct__}