Added serialization for tag-only types

[sandbox] / serial / binary.py

diff --git a/serial/binary.py b/serial/binary.py
new file mode 100644 (file)
index 0000000..2b18bfb
--- /dev/null
+++ b/serial/binary.py
@@ -0,0 +1,51 @@
+import collections
+
+TAG_NULL = 0x00
+TAG_TRUE = 0x01
+TAG_FALSE = 0x02
+
+TaggedObject = collections.namedtuple(
+    'TaggedObject',
+    [
+        'tag',
+        'instance',
+    ],
+)
+
+def _make_tag_only_serializer(tag, expected_value):
+    tag = bytes([tag])
+
+    def serializer(to):
+        assert to.instance == expected_value
+        return tag
+
+    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),
+}
+
+def serialize(to):
+    return _TAGS_TO_SERIALIZERS[to.tag](to)
+
+def _make_tag_only_parser(tag, value):
+    def parser(b):
+        return TaggedObject(tag = tag, instance = value), b
+
+    return parser
+
+_TAGS_TO_PARSERS = {
+    TAG_NULL: _make_tag_only_parser(TAG_NULL, None),
+    TAG_TRUE: _make_tag_only_parser(TAG_TRUE, True),
+    TAG_FALSE: _make_tag_only_parser(TAG_FALSE, False),
+}
+
+def deserialize(b):
+    result, remainder = _TAGS_TO_PARSERS[b[0]](b[1:])
+
+    if len(remainder) == 0:
+        return result
+
+    raise Exception('Unable to parse remainder: {}'.format(remainder))