From 3012060e0d2b5a98805a7c5bb6ef3c60d31f2c4e Mon Sep 17 00:00:00 2001
From: David Kerkeslager <kerkeslager@gmail.com>
Date: Sat, 24 Sep 2016 16:59:10 -0400
Subject: [PATCH] Serialization for unsigned integers

---
 serial/binary.py      | 19 +++++++++++++++++++
 serial/test_binary.py | 31 +++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+)

diff --git a/serial/binary.py b/serial/binary.py
index e8c9093..f6bcff7 100644
--- a/serial/binary.py
+++ b/serial/binary.py
@@ -1,9 +1,15 @@
 import collections
+import functools
 import io
+import struct
 
 TAG_NULL = 0x00
 TAG_TRUE = 0x01
 TAG_FALSE = 0x02
+TAG_UINT8 = 0x03
+TAG_UINT16 = 0x04
+TAG_UINT32 = 0x05
+TAG_UINT64 = 0x06
 
 TaggedObject = collections.namedtuple(
     'TaggedObject',
@@ -22,10 +28,23 @@ def _make_tag_only_serializer(tag, expected_value):
 
     return serializer
 
+def _make_struct_serializer(fmt):
+    fmt = '!B' + fmt
+    packer = functools.partial(struct.pack, fmt)
+
+    def serializer(to):
+        return packer(to.tag, to.instance)
+
+    return serializer
+
 _TAGS_TO_SERIALIZERS = {
     TAG_NULL: _make_tag_only_serializer(TAG_NULL, None),
     TAG_TRUE: _make_tag_only_serializer(TAG_TRUE, True),
     TAG_FALSE: _make_tag_only_serializer(TAG_FALSE, False),
+    TAG_UINT8: _make_struct_serializer('B'),
+    TAG_UINT16: _make_struct_serializer('H'),
+    TAG_UINT32: _make_struct_serializer('I'),
+    TAG_UINT64: _make_struct_serializer('Q'),
 }
 
 def serialize(to):
diff --git a/serial/test_binary.py b/serial/test_binary.py
index b9acaa5..2223ef8 100644
--- a/serial/test_binary.py
+++ b/serial/test_binary.py
@@ -26,6 +26,37 @@ class SerializeTests(unittest.TestCase):
             b'\x02',
         )
 
+    def test_serializes_unsigned_integer_types(self):
+        self.assertEqual(
+            binary.serialize(binary.TaggedObject(
+                tag = binary.TAG_UINT8,
+                instance = 7,
+            )),
+            b'\x03\x07',
+        )
+        self.assertEqual(
+            binary.serialize(binary.TaggedObject(
+                tag = binary.TAG_UINT16,
+                instance = 7,
+            )),
+            b'\x04\x00\x07',
+        )
+        self.assertEqual(
+            binary.serialize(binary.TaggedObject(
+                tag = binary.TAG_UINT32,
+                instance = 7,
+            )),
+            b'\x05\x00\x00\x00\x07',
+        )
+        self.assertEqual(
+            binary.serialize(binary.TaggedObject(
+                tag = binary.TAG_UINT64,
+                instance = 7,
+            )),
+            b'\x06\x00\x00\x00\x00\x00\x00\x00\x07',
+        )
+
+
 class DeserializeTests(unittest.TestCase):
     def test_deserializes_tag_only_types(self):
         self.assertEqual(
-- 
2.20.1