Merge pull request #79 from msgpack/newspec

[WIP] Newspec stage 2.

1 files changed, 12 insertions, 2 deletions

diff --git a/msgpack/__init__.py b/msgpack/__init__.py
index 79107b6..a958025 100644
--- a/msgpack/__init__.py
+++ b/msgpack/__init__.py
@@ -4,7 +4,17 @@ from msgpack.exceptions import *
 
 from collections import namedtuple
 
-ExtType = namedtuple('ExtType', 'code data')
+
+class ExtType(namedtuple('ExtType', 'code data')):
+    def __new__(cls, code, data):
+        if not isinstance(code, int):
+            raise TypeError("code must be int")
+        if not isinstance(data, bytes):
+            raise TypeError("data must be bytes")
+        if not 0 <= code <= 127:
+            raise ValueError("code must be 0~127")
+        return super(ExtType, cls).__new__(cls, code, data)
+
 
 import os
 if os.environ.get('MSGPACK_PUREPYTHON'):
@@ -26,6 +36,7 @@ def pack(o, stream, **kwargs):
     packer = Packer(**kwargs)
     stream.write(packer.pack(o))
 
+
 def packb(o, **kwargs):
     """
     Pack object `o` and return packed bytes
@@ -40,4 +51,3 @@ loads = unpackb
 
 dump = pack
 dumps = packb
-