mojo: Add deserialization to python structs.

mojo/public/python/mojo/bindings/reflection.py

Index: mojo/public/python/mojo/bindings/reflection.py
diff --git a/mojo/public/python/mojo/bindings/reflection.py b/mojo/public/python/mojo/bindings/reflection.py
index d77bdb3abe5b6a86bc67400522a22101f1ff0645..bc8f7a855164b76427680231b899085a34b8b1f3 100644
--- a/mojo/public/python/mojo/bindings/reflection.py
+++ b/mojo/public/python/mojo/bindings/reflection.py
@@ -107,6 +107,14 @@ class MojoStructType(type):
       return serialization_object.Serialize(self, handle_offset)
     dictionary['Serialize'] = Serialize
 
+    def Deserialize(cls, data, handles):
+      result = cls.__new__(cls)
+      fields = {}

[sdefresne, 2014/09/18 12:56:21]

Why not just doing result._fields = {} here? Nothing else has access to result,
so even if an exception is raised, the only way to access result in an
inconsistent state would be to inspect the stack, which I don't expect anyone
sane to do.

[qsr, 2014/09/18 14:16:36]

 Because pylint is a little dumb... If I try to access result._fields for
reading, it complains that I access the private member of an object... Here it
doesn't complain. As pylint is run as a preupload, I need it to be happy.

[sdefresne, 2014/09/18 15:01:49]

Acknowledged. You could do "result._fields = fields = {}". This is valid python
but people find it ugly, so I'm not recommending doing it here.

+      serialization_object.Deserialize(fields, data, handles)
+      result._fields = fields
+      return result
+    dictionary['Deserialize'] = classmethod(Deserialize)
+
     return type.__new__(mcs, name, bases, dictionary)
 
   # Prevent adding new attributes, or mutating constants.