Merge branch 'feature/v0.4' into develop

Conflicts: capnp/capnp.pyx capnp/capnp_cpp.pxd capnp/schema_cpp.pxd setup.py
2013-11-13 22:30:31 -08:00
parent 563cf9c510 ecd2666f96
commit 1ee7326d71
23 changed files with 28778 additions and 182 deletions
--- a/capnp/async_cpp.pxd
+++ b/capnp/async_cpp.pxd
@@ -0,0 +1,18 @@
+# schema.capnp.cpp.pyx
+# distutils: language = c++
+# distutils: extra_compile_args = --std=c++11
+
+from cpython.ref cimport PyObject
+
+cdef extern from "kj/exception.h" namespace " ::kj":
+    cdef cppclass Exception:
+        pass
+        
+cdef extern from "kj/async.h" namespace " ::kj":
+    cdef cppclass Promise[T]:
+        Promise()
+        Promise(Promise)
+        T wait()
+
+ctypedef Promise[PyObject *] PyPromise
+ctypedef Promise[void] VoidPromise
--- a/capnp/capabilityHelper.h
+++ b/capnp/capabilityHelper.h
@@ -0,0 +1,149 @@
+#pragma once
+
+#include "capnp/dynamic.h"
+#include <stdexcept>
+#include "Python.h"
+#include <iostream>
+
+extern "C" {
+   void wrap_remote_call(PyObject * func, capnp::Response<capnp::DynamicStruct> &);
+   PyObject * wrap_dynamic_struct_reader(capnp::DynamicStruct::Reader &);
+   ::kj::Promise<void> * call_server_method(PyObject * py_server, char * name, capnp::CallContext< capnp::DynamicStruct, capnp::DynamicStruct> & context);
+   PyObject * wrap_kj_exception(kj::Exception &);
+   PyObject * wrap_kj_exception_for_reraise(kj::Exception &);
+   PyObject * get_exception_info(PyObject *, PyObject *, PyObject *);
+ }
+
+void reraise_kj_exception() {
+  try {
+    if (PyErr_Occurred())
+      ; // let the latest Python exn pass through and ignore the current one
+    else
+      throw;
+  }
+  catch (kj::Exception& exn) {
+    auto obj = wrap_kj_exception_for_reraise(exn);
+    PyErr_SetObject((PyObject*)obj->ob_type, obj);
+  }
+  catch (const std::exception& exn) {
+    PyErr_SetString(PyExc_RuntimeError, exn.what());
+  }
+  catch (...)
+  {
+    PyErr_SetString(PyExc_RuntimeError, "Unknown exception");
+  }
+}
+
+void check_py_error() {
+    PyObject * err = PyErr_Occurred();
+    if(err) {
+        PyObject * ptype, *pvalue, *ptraceback;
+        PyErr_Fetch(&ptype, &pvalue, &ptraceback);
+
+        PyObject * info = get_exception_info(ptype, pvalue, ptraceback);
+
+        PyObject * py_filename = PyTuple_GetItem(info, 0);
+        kj::String filename(kj::heapString(PyBytes_AsString(py_filename)));
+
+        PyObject * py_line = PyTuple_GetItem(info, 1);
+        int line = PyInt_AsLong(py_line);
+
+        PyObject * py_description = PyTuple_GetItem(info, 2);
+        kj::String description(kj::heapString(PyBytes_AsString(py_description)));
+
+        Py_DECREF(ptype);
+        Py_DECREF(pvalue);
+        Py_DECREF(ptraceback);
+        Py_DECREF(info);
+        PyErr_Clear();
+
+        throw kj::Exception(kj::Exception::Nature::OTHER, kj::Exception::Durability::PERMANENT, kj::mv(filename), line, kj::mv(description));
+    }
+}
+
+PyObject * wrapPyFunc(PyObject * func, PyObject * arg) {
+    PyObject * result = PyObject_CallFunctionObjArgs(func, arg, NULL);
+    Py_DECREF(func);
+
+    check_py_error();
+    return result;
+}
+
+void wrapRemoteCall(PyObject * func, capnp::Response<capnp::DynamicStruct> & arg) {
+    wrap_remote_call(func, arg);
+
+    check_py_error();
+}
+
+::kj::Promise<PyObject *> evalLater(kj::EventLoop & loop, PyObject * func) {
+  return loop.evalLater([func]() { return wrapPyFunc(func, NULL); } );
+}
+
+::kj::Promise<PyObject *> there(kj::EventLoop & loop, kj::Promise<PyObject *> & promise, PyObject * func, PyObject * error_func) {
+  if(error_func == Py_None)
+    return loop.there(kj::mv(promise), [func](PyObject * arg) { return wrapPyFunc(func, arg); } );
+  else
+    return loop.there(kj::mv(promise), [func](PyObject * arg) { return wrapPyFunc(func, arg); } 
+                                     , [error_func](kj::Exception arg) { return wrapPyFunc(error_func, wrap_kj_exception(arg)); } );
+}
+
+::kj::Promise<PyObject *> then(kj::Promise<PyObject *> & promise, PyObject * func, PyObject * error_func) {
+  if(error_func == Py_None)
+    return promise.then([func](PyObject * arg) { return wrapPyFunc(func, arg); } );
+  else
+    return promise.then([func](PyObject * arg) { return wrapPyFunc(func, arg); } 
+                                     , [error_func](kj::Exception arg) { return wrapPyFunc(error_func, wrap_kj_exception(arg)); } );
+}
+
+::kj::Promise<void> then(::capnp::RemotePromise< ::capnp::DynamicStruct> & promise, PyObject * func, PyObject * error_func) {
+  if(error_func == Py_None)
+    return promise.then([func](capnp::Response<capnp::DynamicStruct>&& arg) { wrapRemoteCall(func, arg); } );
+  else
+    return promise.then([func](capnp::Response<capnp::DynamicStruct>&& arg) { wrapRemoteCall(func, arg); } 
+                                     , [error_func](kj::Exception arg) { wrapPyFunc(error_func, wrap_kj_exception(arg)); } );
+}
+
+class PythonInterfaceDynamicImpl final: public capnp::DynamicCapability::Server {
+public:
+  PyObject * py_server;
+
+  PythonInterfaceDynamicImpl(capnp::InterfaceSchema & schema, PyObject * _py_server)
+      : capnp::DynamicCapability::Server(schema), py_server(_py_server) {
+        Py_INCREF(_py_server);
+      }
+
+  ~PythonInterfaceDynamicImpl() {
+    Py_DECREF(py_server);
+  }
+
+  kj::Promise<void> call(capnp::InterfaceSchema::Method method,
+                         capnp::CallContext< capnp::DynamicStruct, capnp::DynamicStruct> context) {
+    auto methodName = method.getProto().getName();
+
+    kj::Promise<void> * promise = call_server_method(py_server, const_cast<char *>(methodName.cStr()), context);
+
+    check_py_error();
+
+    if(promise == nullptr)
+      return kj::READY_NOW;
+
+    kj::Promise<void> ret(kj::mv(*promise));
+    delete promise;
+    return ret;
+  }
+};
+
+capnp::DynamicCapability::Client new_client(capnp::InterfaceSchema & schema, PyObject * server, kj::EventLoop & loop) {
+  return capnp::DynamicCapability::Client(kj::heap<PythonInterfaceDynamicImpl>(schema, server), loop);
+}
+capnp::DynamicValue::Reader new_server(capnp::InterfaceSchema & schema, PyObject * server) {
+  return capnp::DynamicValue::Reader(kj::heap<PythonInterfaceDynamicImpl>(schema, server));
+}
+
+capnp::Capability::Client server_to_client(capnp::InterfaceSchema & schema, PyObject * server) {
+  return kj::heap<PythonInterfaceDynamicImpl>(schema, server);
+}
+
+::kj::Promise<PyObject *> convert_to_pypromise(capnp::RemotePromise<capnp::DynamicStruct> & promise) {
+    return promise.then([](capnp::Response<capnp::DynamicStruct>&& response) { return wrap_dynamic_struct_reader(response); } );
+}
--- a/capnp/capnp.pyx
+++ b/capnp/capnp.pyx
--- a/capnp/capnp_cpp.pxd
+++ b/capnp/capnp_cpp.pxd
@@ -1,24 +1,43 @@
 # schema.capnp.cpp.pyx
 # distutils: language = c++
 # distutils: extra_compile_args = --std=c++11
-from schema_cpp cimport Node, Data, StructNode, EnumNode
+from schema_cpp cimport Node, Data, StructNode, EnumNode, InterfaceNode, MessageBuilder, MessageReader
+from async_cpp cimport PyPromise, VoidPromise, Promise

+from cpython.ref cimport PyObject
 from libc.stdint cimport *
 ctypedef unsigned int uint
 from libcpp cimport bool as cbool

+cdef extern from "capabilityHelper.h":
+    void reraise_kj_exception()
+
 cdef extern from "capnp/common.h" namespace " ::capnp":
    enum Void:
        VOID " ::capnp::VOID"
-    cdef cppclass word:
-        pass

 cdef extern from "kj/string.h" namespace " ::kj":
    cdef cppclass StringPtr:
        StringPtr(char *)
+        char* cStr()
    cdef cppclass String:
        char* cStr()

+cdef extern from "kj/exception.h" namespace " ::kj":
+    cdef cppclass Exception:
+        Exception(Exception)
+        char* getFile()
+        int getLine()
+        int getNature()
+        int getDurability()
+        StringPtr getDescription()
+
+cdef extern from "kj/memory.h" namespace " ::kj":    
+    cdef cppclass Own[T]:
+        T& operator*()
+    Own[TwoPartyVatNetwork] makeTwoPartyVatNetwork" ::kj::heap< ::capnp::TwoPartyVatNetwork>"(EventLoop &, AsyncIoStream& stream, Side)
+    Own[PromiseFulfillerPair] copyPromiseFulfillerPair" ::kj::heap< ::kj::PromiseFulfillerPair<void> >"(PromiseFulfillerPair&)
+
 cdef extern from "kj/string-tree.h" namespace " ::kj":
    cdef cppclass StringTree:
        String flatten()
@@ -32,31 +51,42 @@ cdef extern from "kj/common.h" namespace " ::kj":
        size_t size()
        T& operator[](size_t index)

-    # Cython can't handle ArrayPtr[word] as a function argument
-    cdef cppclass WordArrayPtr " ::kj::ArrayPtr< ::capnp::word>":
-        WordArrayPtr()
-        WordArrayPtr(word *, size_t size)
-        size_t size()
-        word& operator[](size_t index)
-
 cdef extern from "kj/array.h" namespace " ::kj":
    cdef cppclass Array[T]:
        T* begin()
        size_t size()

-    # Cython can't handle Array[word] as a function argument
-    cdef cppclass WordArray " ::kj::Array< ::capnp::word>":
-        word* begin()
-        size_t size()
+cdef extern from "kj/async-io.h" namespace " ::kj":
+    cdef cppclass AsyncIoStream:
+        pass
+
+    Own[AsyncIoStream] AsyncIoStream_wrapFd" ::kj::AsyncIoStream::wrapFd"(int)

 cdef extern from "capnp/schema.h" namespace " ::capnp":
    cdef cppclass Schema:
-        Node.Reader getProto() except +
-        StructSchema asStruct() except +
-        EnumSchema asEnum() except +
-        ConstSchema asConst() except +
-        Schema getDependency(uint64_t id) except +
-        #InterfaceSchema asInterface() const;
+        Node.Reader getProto() except +reraise_kj_exception
+        StructSchema asStruct() except +reraise_kj_exception
+        EnumSchema asEnum() except +reraise_kj_exception
+        ConstSchema asConst() except +reraise_kj_exception
+        Schema getDependency(uint64_t id) except +reraise_kj_exception
+        InterfaceSchema asInterface() except +reraise_kj_exception
+
+    cdef cppclass InterfaceSchema(Schema):
+        cppclass Method:
+            InterfaceNode.Method.Reader getProto()
+            InterfaceSchema getContainingInterface()
+            uint16_t getOrdinal()
+            uint getIndex()
+
+        cppclass MethodList:
+            uint size()
+            Method operator[](uint index)
+
+        MethodList getMethods()
+        Maybe[Method] findMethodByName(StringPtr name)
+        Method getMethodByName(StringPtr name)
+        bint extends(InterfaceSchema other)
+        # kj::Maybe<InterfaceSchema> findSuperclass(uint64_t typeId) const;

    cdef cppclass StructSchema(Schema):
        cppclass Field:
@@ -103,6 +133,8 @@ cdef extern from "capnp/dynamic.h" namespace " ::capnp":
            pass
        cppclass Builder:
            pass
+        cppclass Pipeline:
+            pass

    enum Type:
        TYPE_UNKNOWN " ::capnp::DynamicValue::UNKNOWN"
@@ -116,34 +148,110 @@ cdef extern from "capnp/dynamic.h" namespace " ::capnp":
        TYPE_LIST " ::capnp::DynamicValue::LIST"
        TYPE_ENUM " ::capnp::DynamicValue::ENUM"
        TYPE_STRUCT " ::capnp::DynamicValue::STRUCT"
-        TYPE_INTERFACE " ::capnp::DynamicValue::INTERFACE"
+        TYPE_CAPABILITY " ::capnp::DynamicValue::CAPABILITY"
        TYPE_OBJECT " ::capnp::DynamicValue::OBJECT"

    cdef cppclass DynamicStruct:
        cppclass Reader:
-            DynamicValueForward.Reader get(char *) except +ValueError
-            bint has(char *) except +ValueError
+            DynamicValueForward.Reader get(char *) except +reraise_kj_exception
+            bint has(char *) except +reraise_kj_exception
            StructSchema getSchema()
            Maybe[StructSchema.Field] which()
        cppclass Builder:
            Builder()
            Builder(Builder &)
-            DynamicValueForward.Builder get(char *) except +ValueError
-            bint has(char *) except +ValueError
-            void set(char *, DynamicValueForward.Reader) except +ValueError
-            DynamicValueForward.Builder init(char *, uint size) except +ValueError
-            DynamicValueForward.Builder init(char *) except +ValueError
+            DynamicValueForward.Builder get(char *) except +reraise_kj_exception
+            bint has(char *) except +reraise_kj_exception
+            void set(char *, DynamicValueForward.Reader) except +reraise_kj_exception
+            DynamicValueForward.Builder init(char *, uint size) except +reraise_kj_exception
+            DynamicValueForward.Builder init(char *) except +reraise_kj_exception
            StructSchema getSchema()
            Maybe[StructSchema.Field] which()
-            void adopt(char *, DynamicOrphan) except +ValueError
+            void adopt(char *, DynamicOrphan) except +reraise_kj_exception
            DynamicOrphan disown(char *)
            DynamicStruct.Reader asReader()
-            DynamicStruct.Builder getObject(char *, StructSchema)
+        cppclass Pipeline:
+            Pipeline()
+            Pipeline(Pipeline &)
+            DynamicValueForward.Pipeline get(char *)
+            StructSchema getSchema()
+
+cdef extern from "capnp/dynamic.h" namespace " ::capnp":
+    cdef cppclass DynamicCapability:
+        cppclass Client:
+            Client()
+            Client(Client&)
+            Client upcast(InterfaceSchema requestedSchema)
+            DynamicCapability.Client castAs"castAs< ::capnp::DynamicCapability>"(InterfaceSchema)
+            InterfaceSchema getSchema()
+            Request newRequest(char * methodName, uint firstSegmentWordSize)
+
+cdef extern from "capnp/capability.h" namespace " ::capnp":
+    cdef cppclass Response" ::capnp::Response< ::capnp::DynamicStruct>"(DynamicStruct.Reader):
+        Response(Response)
+    cdef cppclass RemotePromise" ::capnp::RemotePromise< ::capnp::DynamicStruct>"(Promise[Response], DynamicStruct.Pipeline):
+        RemotePromise(RemotePromise)
+    cdef cppclass Capability:
+        cppclass Client:
+            Client(Client&)
+            DynamicCapability.Client castAs"castAs< ::capnp::DynamicCapability>"(InterfaceSchema)
+
+cdef extern from "capnp/rpc-twoparty.h" namespace " ::capnp":
+    cdef cppclass RpcSystem" ::capnp::RpcSystem<capnp::rpc::twoparty::SturdyRefHostId>":
+        RpcSystem(RpcSystem&&)
+    enum Side" ::capnp::rpc::twoparty::Side":
+        CLIENT" ::capnp::rpc::twoparty::Side::CLIENT"
+        SERVER" ::capnp::rpc::twoparty::Side::SERVER"
+    cdef cppclass TwoPartyVatNetwork:
+        TwoPartyVatNetwork(EventLoop &, AsyncIoStream& stream, Side)
+    RpcSystem makeRpcServer(TwoPartyVatNetwork&, PyRestorer&, EventLoop&)
+    RpcSystem makeRpcClient(TwoPartyVatNetwork&, EventLoop&)
+
+cdef extern from "capnp/dynamic.h" namespace " ::capnp":
+    cdef cppclass Request" ::capnp::Request< ::capnp::DynamicStruct, ::capnp::DynamicStruct>":
+        Request()
+        Request(Request &)
+        DynamicValueForward.Builder get(char *) except +reraise_kj_exception
+        bint has(char *) except +reraise_kj_exception
+        void set(char *, DynamicValueForward.Reader) except +reraise_kj_exception
+        DynamicValueForward.Builder init(char *, uint size) except +reraise_kj_exception
+        DynamicValueForward.Builder init(char *) except +reraise_kj_exception
+        StructSchema getSchema()
+        Maybe[StructSchema.Field] which()
+        RemotePromise send()
+
+cdef extern from "capnp/object.h" namespace " ::capnp":
+    cdef cppclass ObjectPointer:
+        cppclass Reader:
+            DynamicStruct.Reader getAs"getAs< ::capnp::DynamicStruct>"(StructSchema)
+        cppclass Builder:
+            Builder(Builder)
+            DynamicStruct.Builder getAs"getAs< ::capnp::DynamicStruct>"(StructSchema)

 cdef extern from "fixMaybe.h":
-    EnumSchema.Enumerant fixMaybe(Maybe[EnumSchema.Enumerant]) except +ValueError
+    EnumSchema.Enumerant fixMaybe(Maybe[EnumSchema.Enumerant]) except +reraise_kj_exception
    char * getEnumString(DynamicStruct.Reader val)
    char * getEnumString(DynamicStruct.Builder val)
+    char * getEnumString(Request val)
+
+cdef extern from "capabilityHelper.h":
+    PyPromise evalLater(EventLoop &, PyObject * func)
+    PyPromise there(EventLoop & loop, PyPromise & promise, PyObject * func, PyObject * error_func)
+    PyPromise then(PyPromise & promise, PyObject * func, PyObject * error_func)
+    VoidPromise then(RemotePromise & promise, PyObject * func, PyObject * error_func)
+    cppclass PythonInterfaceDynamicImpl:
+        PythonInterfaceDynamicImpl(PyObject *)
+    DynamicCapability.Client new_client(InterfaceSchema&, PyObject *, EventLoop&)
+    DynamicValueForward.Reader new_server(InterfaceSchema&, PyObject *)
+    Capability.Client server_to_client(InterfaceSchema&, PyObject *)
+    PyPromise convert_to_pypromise(RemotePromise&)
+
+cdef extern from "rpcHelper.h":
+    cdef cppclass PyRestorer:
+        PyRestorer(PyObject *, StructSchema&)
+    Capability.Client restoreHelper(RpcSystem&, MessageBuilder&)
+    Capability.Client restoreHelper(RpcSystem&, MessageReader&)
+    RpcSystem makeRpcClientWithRestorer(TwoPartyVatNetwork&, EventLoop&, PyRestorer&)

 cdef extern from "capnp/dynamic.h" namespace " ::capnp":
    cdef cppclass DynamicEnum:
@@ -159,16 +267,16 @@ cdef extern from "capnp/dynamic.h" namespace " ::capnp":

    cdef cppclass DynamicList:
        cppclass Reader:
-            DynamicValueForward.Reader operator[](uint) except +ValueError
+            DynamicValueForward.Reader operator[](uint) except +reraise_kj_exception
            uint size()
        cppclass Builder:
            Builder()
            Builder(Builder &)
-            DynamicValueForward.Builder operator[](uint) except +ValueError
+            DynamicValueForward.Builder operator[](uint) except +reraise_kj_exception
            uint size()
-            void set(uint index, DynamicValueForward.Reader value) except +ValueError
-            DynamicValueForward.Builder init(uint index, uint size) except +ValueError
-            void adopt(uint, DynamicOrphan) except +ValueError
+            void set(uint index, DynamicValueForward.Reader value) except +reraise_kj_exception
+            DynamicValueForward.Builder init(uint index, uint size) except +reraise_kj_exception
+            void adopt(uint, DynamicOrphan) except +reraise_kj_exception
            DynamicOrphan disown(uint)
            StructSchema getStructElementType'getSchema().getStructElementType'()

@@ -193,39 +301,88 @@ cdef extern from "capnp/dynamic.h" namespace " ::capnp":
            Reader(DynamicList.Reader& value)
            Reader(DynamicEnum value)
            Reader(DynamicStruct.Reader& value)
+            Reader(DynamicCapability.Client& value)
+            Reader(PythonInterfaceDynamicImpl& value)
            Type getType()
            int64_t asInt"as<int64_t>"()
            uint64_t asUint"as<uint64_t>"()
            bint asBool"as<bool>"()
            double asDouble"as<double>"()
-            char * asText"as< ::capnp::Text>().cStr"()
+            String asText"as< ::capnp::Text>"()
            DynamicList.Reader asList"as< ::capnp::DynamicList>"()
            DynamicStruct.Reader asStruct"as< ::capnp::DynamicStruct>"()
-            DynamicObject.Reader asObject"as< ::capnp::DynamicObject>"()
+            ObjectPointer.Reader asObject"as< ::capnp::ObjectPointer>"()
+            DynamicCapability.Client asCapability"as< ::capnp::DynamicCapability>"()
            DynamicEnum asEnum"as< ::capnp::DynamicEnum>"()
            Data.Reader asData"as< ::capnp::Data>"()

        cppclass Builder:
-            Builder()
            Type getType()
            int64_t asInt"as<int64_t>"()
            uint64_t asUint"as<uint64_t>"()
            bint asBool"as<bool>"()
            double asDouble"as<double>"()
-            char * asText"as< ::capnp::Text>().cStr"()
+            String asText"as< ::capnp::Text>"()
            DynamicList.Builder asList"as< ::capnp::DynamicList>"()
            DynamicStruct.Builder asStruct"as< ::capnp::DynamicStruct>"()
+            ObjectPointer.Builder asObject"as< ::capnp::ObjectPointer>"()
+            DynamicCapability.Client asCapability"as< ::capnp::DynamicCapability>"()
            DynamicEnum asEnum"as< ::capnp::DynamicEnum>"()
            Data.Builder asData"as< ::capnp::Data>"()

+        cppclass Pipeline:
+            Pipeline(Pipeline)
+            DynamicCapability.Client asCapability"releaseAs< ::capnp::DynamicCapability>"()
+            DynamicStruct.Pipeline asStruct"releaseAs< ::capnp::DynamicStruct>"()
+            Type getType()
+
 cdef extern from "capnp/schema-parser.h" namespace " ::capnp":
    cdef cppclass ParsedSchema(Schema):
-        ParsedSchema getNested(char * name) except +
+        ParsedSchema getNested(char * name) except +reraise_kj_exception
    cdef cppclass SchemaParser:
        SchemaParser()
-        ParsedSchema parseDiskFile(char * displayName, char * diskPath, ArrayPtr[StringPtr] importPath) except +
+        ParsedSchema parseDiskFile(char * displayName, char * diskPath, ArrayPtr[StringPtr] importPath) except +reraise_kj_exception

 cdef extern from "capnp/orphan.h" namespace " ::capnp":
    cdef cppclass DynamicOrphan" ::capnp::Orphan< ::capnp::DynamicValue>":
        DynamicValue.Builder get()
        DynamicValue.Reader getReader()
+
+cdef extern from "capnp/capability.h" namespace " ::capnp":
+    cdef cppclass CallContext' ::capnp::CallContext< ::capnp::DynamicStruct, ::capnp::DynamicStruct>':
+        CallContext(CallContext&)
+        DynamicStruct.Reader getParams() except +reraise_kj_exception
+        void releaseParams()
+
+        DynamicStruct.Builder getResults(uint firstSegmentWordSize)
+        DynamicStruct.Builder initResults(uint firstSegmentWordSize)
+        void setResults(DynamicStruct.Reader value)
+        # void adoptResults(Orphan<Results>&& value);
+        # Orphanage getResultsOrphanage(uint firstSegmentWordSize = 0);
+        void allowAsyncCancellation(bint allow = true)
+        bint isCanceled()
+
+cdef extern from "kj/async.h" namespace " ::kj":
+    cdef cppclass EventLoop:
+        EventLoop()
+        # Promise[void] yield_end'yield'()
+        object wait(PyPromise) except +reraise_kj_exception
+        Response wait_remote'wait'(RemotePromise)
+        void wait_void'wait'(VoidPromise)
+        object there(PyPromise) except +reraise_kj_exception
+        PyPromise evalLater(PyObject * func)
+        PyPromise there(PyPromise, PyObject * func)
+    cdef cppclass SimpleEventLoop(EventLoop):
+        pass
+    cdef cppclass PromiseFulfiller:
+        pass
+    cdef cppclass PromiseFulfillerPair" ::kj::PromiseFulfillerPair<void>":
+        VoidPromise promise
+        Own[PromiseFulfiller] fulfiller
+    PromiseFulfillerPair newPromiseAndFulfiller" ::kj::newPromiseAndFulfiller<void>"()
+    PromiseFulfillerPair newPromiseAndFulfiller" ::kj::newPromiseAndFulfiller<void>"(EventLoop&)
+
+cdef extern from "kj/async-unix.h" namespace " ::kj":
+    cdef cppclass UnixEventLoop(EventLoop):
+        pass
+
--- a/capnp/fixMaybe.h
+++ b/capnp/fixMaybe.h
@@ -13,7 +13,7 @@ T fixMaybe(::kj::Maybe<T> val) {
 }

 template<typename T>
-const char * getEnumString(T val) {
+const char * getEnumString(T & val) {

  auto maybe_val = val.which();
  KJ_IF_MAYBE(new_val, maybe_val) {
--- a/capnp/rpcHelper.h
+++ b/capnp/rpcHelper.h
@@ -0,0 +1,59 @@
+#pragma once
+
+#include "capnp/dynamic.h"
+#include "capnp/rpc-twoparty.h"
+#include "Python.h"
+#include "capabilityHelper.h"
+
+extern "C" {
+   capnp::Capability::Client * call_py_restorer(PyObject *, capnp::DynamicStruct::Reader &);
+}
+
+class PyRestorer final: public capnp::SturdyRefRestorer<capnp::ObjectPointer> {
+public:
+  PyRestorer(PyObject * _py_restorer, capnp::StructSchema& _schema): py_restorer(_py_restorer), schema(_schema) {
+    // We don't need to incref/decref, since this C++ class will be owned by the Python wrapper class, and we'll make sure the python class doesn't refcount to 0 elsewhere.
+    // Py_INCREF(py_restorer);
+  }
+
+  // ~PyRestorer() {
+  //   Py_DECREF(py_restorer);
+  // }
+  
+  capnp::Capability::Client restore(capnp::ObjectPointer::Reader objectId) override {
+    auto reader = objectId.getAs<capnp::DynamicStruct>(schema);
+    capnp::Capability::Client * ret = call_py_restorer(py_restorer, reader);
+    check_py_error();
+    capnp::Capability::Client stack_ret(*ret);
+    delete ret;
+
+    return stack_ret;
+  }
+
+private:
+  PyObject * py_restorer;
+  capnp::StructSchema schema;
+};
+
+capnp::Capability::Client restoreHelper(capnp::RpcSystem<capnp::rpc::twoparty::SturdyRefHostId>& client, capnp::MessageBuilder & objectId) {  capnp::MallocMessageBuilder hostIdMessage(8);
+    auto hostId = hostIdMessage.initRoot<capnp::rpc::twoparty::SturdyRefHostId>();
+    hostId.setSide(capnp::rpc::twoparty::Side::SERVER);
+    return client.restore(hostId, objectId.getRoot<capnp::ObjectPointer>());
+}
+
+
+capnp::Capability::Client restoreHelper(capnp::RpcSystem<capnp::rpc::twoparty::SturdyRefHostId>& client, capnp::MessageReader & objectId) {  capnp::MallocMessageBuilder hostIdMessage(8);
+    auto hostId = hostIdMessage.initRoot<capnp::rpc::twoparty::SturdyRefHostId>();
+    hostId.setSide(capnp::rpc::twoparty::Side::SERVER);
+    return client.restore(hostId, objectId.getRoot<capnp::ObjectPointer>());
+}
+
+template <typename SturdyRefHostId, typename ProvisionId,
+          typename RecipientId, typename ThirdPartyCapId, typename JoinAnswer>
+capnp::RpcSystem<SturdyRefHostId> makeRpcClientWithRestorer(
+    capnp::VatNetwork<SturdyRefHostId, ProvisionId, RecipientId, ThirdPartyCapId, JoinAnswer>& network,
+    const kj::EventLoop& eventLoop, PyRestorer& restorer) {
+    using namespace capnp;
+  return RpcSystem<SturdyRefHostId>(network,
+      kj::Maybe<SturdyRefRestorer<ObjectPointer>&>(restorer), eventLoop);
+}
--- a/capnp/schema_cpp.pxd
+++ b/capnp/schema_cpp.pxd
@@ -5,7 +5,6 @@

 from libc.stdint cimport *
 from capnp_cpp cimport DynamicOrphan
-cimport capnp_cpp
 ctypedef unsigned int uint
 ctypedef uint8_t UInt8
 ctypedef uint16_t UInt16
@@ -689,28 +688,49 @@ cdef extern from "capnp/message.h" namespace " ::capnp":
        MallocMessageBuilder(int)

    cdef cppclass FlatMessageBuilder(MessageBuilder):
-        FlatMessageBuilder(capnp_cpp.WordArrayPtr array)
-        FlatMessageBuilder(capnp_cpp.WordArrayPtr array, ReaderOptions)
+        FlatMessageBuilder(WordArrayPtr array)
+        FlatMessageBuilder(WordArrayPtr array, ReaderOptions)

    enum Void:
        VOID

+cdef extern from "capnp/common.h" namespace " ::capnp":
+    cdef cppclass word:
+        pass
+
+cdef extern from "kj/common.h" namespace " ::kj":
+    # Cython can't handle ArrayPtr[word] as a function argument
+    cdef cppclass WordArrayPtr " ::kj::ArrayPtr< ::capnp::word>":
+        WordArrayPtr()
+        WordArrayPtr(word *, size_t size)
+        size_t size()
+        word& operator[](size_t index)
+
+cdef extern from "kj/array.h" namespace " ::kj":
+    # Cython can't handle Array[word] as a function argument
+    cdef cppclass WordArray " ::kj::Array< ::capnp::word>":
+        word* begin()
+        size_t size()
+
+cdef extern from "capabilityHelper.h":
+    void reraise_kj_exception()
+    
 cdef extern from "capnp/serialize.h" namespace " ::capnp":
    cdef cppclass StreamFdMessageReader(MessageReader):
-        StreamFdMessageReader(int) except +
-        StreamFdMessageReader(int, ReaderOptions) except +
+        StreamFdMessageReader(int) except +reraise_kj_exception
+        StreamFdMessageReader(int, ReaderOptions) except +reraise_kj_exception

    cdef cppclass FlatArrayMessageReader(MessageReader):
-        FlatArrayMessageReader(capnp_cpp.WordArrayPtr array) except +
-        FlatArrayMessageReader(capnp_cpp.WordArrayPtr array, ReaderOptions) except +
+        FlatArrayMessageReader(WordArrayPtr array) except +reraise_kj_exception
+        FlatArrayMessageReader(WordArrayPtr array, ReaderOptions) except +reraise_kj_exception

-    void writeMessageToFd(int, MessageBuilder&) except +
+    void writeMessageToFd(int, MessageBuilder&) except +reraise_kj_exception

-    capnp_cpp.WordArray messageToFlatArray(MessageBuilder &)
+    WordArray messageToFlatArray(MessageBuilder &)

 cdef extern from "capnp/serialize-packed.h" namespace " ::capnp":
    cdef cppclass PackedFdMessageReader(MessageReader):
-        PackedFdMessageReader(int) except +
-        PackedFdMessageReader(int, ReaderOptions) except +
+        PackedFdMessageReader(int) except +reraise_kj_exception
+        PackedFdMessageReader(int, ReaderOptions) except +reraise_kj_exception

-    void writePackedMessageToFd(int, MessageBuilder&) except +
+    void writePackedMessageToFd(int, MessageBuilder&) except +reraise_kj_exception
--- a/examples/c++.capnp
+++ b/examples/c++.capnp
@@ -0,0 +1,27 @@
+# Copyright (c) 2013, Kenton Varda <temporal@gmail.com>
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice, this
+#    list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+#    this list of conditions and the following disclaimer in the documentation
+#    and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+@0xbdf87d7bb8304e81;
+$namespace("capnp::annotations");
+
+annotation namespace(file): Text;
--- a/examples/example_capability.capnp
+++ b/examples/example_capability.capnp
@@ -0,0 +1,58 @@
+# Copyright (c) 2013, Kenton Varda <temporal@gmail.com>
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice, this
+#    list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+#    this list of conditions and the following disclaimer in the documentation
+#    and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+@0xd508eefec2dc42b8;
+
+interface TestInterface {
+  foo @0 (i :UInt32, j :Bool) -> (x: Text);
+  bar @1 () -> ();
+  # baz @2 (s: TestAllTypes);
+}
+
+interface TestExtends extends(TestInterface) {
+  qux @0 ();
+#   corge @1 TestAllTypes -> ();
+#   grault @2 () -> TestAllTypes;
+}
+
+interface TestPipeline {
+  getCap @0 (n: UInt32, inCap :TestInterface) -> (s: Text, outBox :Box);
+  testPointers @1 (cap :TestInterface, obj :Object, list :List(TestInterface)) -> ();
+
+  struct Box {
+    cap @0 :TestInterface;
+  }
+}
+
+struct TestSturdyRefHostId {
+  host @0 :Text;
+}
+
+struct TestSturdyRefObjectId {
+  tag @0 :Tag;
+  enum Tag {
+    testInterface @0;
+    testExtends @1;
+    testPipeline @2;
+  }
+}
--- a/examples/example_capability.py
+++ b/examples/example_capability.py
@@ -0,0 +1,37 @@
+from __future__ import print_function
+
+import capnp
+import example_capability_capnp as capability
+import socket
+
+class Server:
+    def __init__(self, val=1):
+        self.val = val
+
+    def foo(self, context):
+        context.results.x = str(context.params.i * 5 + self.val)
+
+def example_simple_rpc():
+    def _restore(ref_id):
+        return capability.TestInterface.new_server(Server(100))
+
+    loop = capnp.EventLoop()
+    
+    read, write = socket.socketpair(socket.AF_UNIX)
+    read_stream = capnp.FdAsyncIoStream(read.fileno())
+    write_stream = capnp.FdAsyncIoStream(write.fileno())
+
+    restorer = capnp.Restorer(capability.TestSturdyRefObjectId, _restore)
+    server = capnp.RpcServer(loop, write_stream, restorer)
+    client = capnp.RpcClient(loop, read_stream)
+
+    ref = capability.TestSturdyRefObjectId.new_message()
+    cap = client.restore(ref.as_reader())
+    cap = cap.cast_as(capability.TestInterface)
+
+    remote = cap.foo(i=5)
+    response = loop.wait(remote)
+
+    assert response.x == '125'
+
+example_simple_rpc()
--- a/examples/example_client.cpp
+++ b/examples/example_client.cpp
@@ -0,0 +1,59 @@
+#include "capnp/rpc-twoparty.h"
+#include <kj/async-unix.h>
+#include <kj/thread.h>
+#include "test.capnp.h"
+#include <iostream>
+#include <cassert>
+
+using namespace capnp;
+using namespace capnproto_test::capnp;
+using namespace kj;
+
+Capability::Client getPersistentCap(RpcSystem<rpc::twoparty::SturdyRefHostId>& client,
+                                    rpc::twoparty::Side side,
+                                    test::TestSturdyRefObjectId::Tag tag) {
+  // Create the SturdyRefHostId.
+  MallocMessageBuilder hostIdMessage(8);
+  auto hostId = hostIdMessage.initRoot<rpc::twoparty::SturdyRefHostId>();
+  hostId.setSide(side);
+
+  // Create the SturdyRefObjectId.
+  MallocMessageBuilder objectIdMessage(8);
+  objectIdMessage.initRoot<test::TestSturdyRefObjectId>().setTag(tag);
+
+  // Connect to the remote capability.
+  return client.restore(hostId, objectIdMessage.getRoot<ObjectPointer>());
+}
+
+int main()
+{
+  try
+  {
+    kj::UnixEventLoop loop;
+    auto result = loop.evalLater([&]() {
+      auto network = Network::newSystemNetwork();
+      auto address = loop.wait(network->parseRemoteAddress("127.0.0.1:49999"));
+      auto stream = loop.wait(address->connect());
+      TwoPartyVatNetwork vat(loop, *stream, rpc::twoparty::Side::CLIENT);
+      auto rpcClient = makeRpcClient(vat, loop);
+
+      // Request the particular capability from the server.
+      auto client = getPersistentCap(rpcClient, rpc::twoparty::Side::SERVER,
+          test::TestSturdyRefObjectId::Tag::TEST_INTERFACE).castAs<test::TestInterface>();
+
+      auto request1 = client.fooRequest();
+      request1.setI(5);
+      auto promise1 = request1.send();
+      auto response1 = loop.wait(kj::mv(promise1));
+
+      assert ("125" == response1.getX()); 
+    });
+
+    loop.wait(kj::mv(result));
+  }
+  catch (std::exception& e)
+  {
+    std::cerr << e.what() << std::endl;
+  }
+    return 0;
+}
--- a/examples/example_client.py
+++ b/examples/example_client.py
@@ -0,0 +1,26 @@
+from __future__ import print_function
+
+import capnp
+import test_capnp
+import socket
+
+def example_client():
+    loop = capnp.EventLoop()
+    
+    c = socket.create_connection(('localhost', 49999))
+    read_stream = capnp.FdAsyncIoStream(c.fileno())
+
+    client = capnp.RpcClient(loop, read_stream)
+
+    ref = test_capnp.TestSturdyRefObjectId.new_message()
+    ref.tag = 'testInterface'
+    cap = client.restore(ref)
+    cap = cap.cast_as(test_capnp.TestInterface)
+
+    remote = cap.foo(i=5)
+    response = loop.wait(remote)
+
+    assert response.x == '125'
+    c.close()
+
+example_client()
--- a/examples/example_server.cpp
+++ b/examples/example_server.cpp
@@ -0,0 +1,190 @@
+#include <boost/asio.hpp>
+#include "capnp/rpc-twoparty.h"
+#include <kj/async-unix.h>
+#include <kj/thread.h>
+#include "test.capnp.h"
+
+using namespace capnp;
+using namespace capnproto_test::capnp;
+using namespace kj;
+
+class TestInterfaceImpl final: public test::TestInterface::Server {
+public:
+  TestInterfaceImpl(int& callCount);
+
+  ::kj::Promise<void> foo(
+      test::TestInterface::FooParams::Reader params,
+      test::TestInterface::FooResults::Builder result) override;
+
+  ::kj::Promise<void> bazAdvanced(
+      ::capnp::CallContext<test::TestInterface::BazParams,
+                           test::TestInterface::BazResults> context) override;
+
+private:
+  int& callCount;
+};
+
+class TestExtendsImpl final: public test::TestExtends::Server {
+public:
+  TestExtendsImpl(int& callCount);
+
+  ::kj::Promise<void> foo(
+      test::TestInterface::FooParams::Reader params,
+      test::TestInterface::FooResults::Builder result) override;
+
+  ::kj::Promise<void> graultAdvanced(
+      ::capnp::CallContext<test::TestExtends::GraultParams, test::TestAllTypes> context) override;
+
+private:
+  int& callCount;
+};
+
+class TestPipelineImpl final: public test::TestPipeline::Server {
+public:
+  TestPipelineImpl(int& callCount);
+
+  ::kj::Promise<void> getCapAdvanced(
+      capnp::CallContext<test::TestPipeline::GetCapParams,
+                         test::TestPipeline::GetCapResults> context) override;
+
+private:
+  int& callCount;
+};
+
+
+TestInterfaceImpl::TestInterfaceImpl(int& callCount): callCount(callCount) {}
+
+::kj::Promise<void> TestInterfaceImpl::foo(
+    test::TestInterface::FooParams::Reader params,
+    test::TestInterface::FooResults::Builder result) {
+  ++callCount;
+  result.setX("foo");
+  return kj::READY_NOW;
+}
+
+::kj::Promise<void> TestInterfaceImpl::bazAdvanced(
+    ::capnp::CallContext<test::TestInterface::BazParams,
+                         test::TestInterface::BazResults> context) {
+  ++callCount;
+  auto params = context.getParams();
+  // checkTestMessage(params.getS());
+  context.releaseParams();
+
+  return kj::READY_NOW;
+}
+
+TestExtendsImpl::TestExtendsImpl(int& callCount): callCount(callCount) {}
+
+::kj::Promise<void> TestExtendsImpl::foo(
+    test::TestInterface::FooParams::Reader params,
+    test::TestInterface::FooResults::Builder result) {
+  ++callCount;
+  result.setX("bar");
+  return kj::READY_NOW;
+}
+
+::kj::Promise<void> TestExtendsImpl::graultAdvanced(
+    ::capnp::CallContext<test::TestExtends::GraultParams, test::TestAllTypes> context) {
+  ++callCount;
+  context.releaseParams();
+
+  // initTestMessage(context.getResults());
+
+  return kj::READY_NOW;
+}
+
+TestPipelineImpl::TestPipelineImpl(int& callCount): callCount(callCount) {}
+
+::kj::Promise<void> TestPipelineImpl::getCapAdvanced(
+    capnp::CallContext<test::TestPipeline::GetCapParams,
+                       test::TestPipeline::GetCapResults> context) {
+  ++callCount;
+
+  auto params = context.getParams();
+
+  auto cap = params.getInCap();
+  context.releaseParams();
+
+  auto request = cap.fooRequest();
+  request.setI(123);
+  request.setJ(true);
+
+  return request.send().then(
+      [this,context](capnp::Response<test::TestInterface::FooResults>&& response) mutable {
+
+        auto result = context.getResults();
+        result.setS("bar");
+        result.initOutBox().setCap(kj::heap<TestExtendsImpl>(callCount));
+      });
+}
+
+
+class TestRestorer final: public SturdyRefRestorer<test::TestSturdyRefObjectId> {
+public:
+  TestRestorer(int& callCount): callCount(callCount) {}
+
+  Capability::Client restore(test::TestSturdyRefObjectId::Reader objectId) override {
+    switch (objectId.getTag()) {
+      case test::TestSturdyRefObjectId::Tag::TEST_INTERFACE:
+        return kj::heap<TestInterfaceImpl>(callCount);
+      // case test::TestSturdyRefObjectId::Tag::TEST_EXTENDS:
+      //   return Capability::Client(newBrokenCap("No TestExtends implemented."));
+      case test::TestSturdyRefObjectId::Tag::TEST_PIPELINE:
+        return kj::heap<TestPipelineImpl>(callCount);
+    }
+    KJ_UNREACHABLE;
+  }
+
+private:
+  int& callCount;
+};
+
+void runServer(kj::Promise<void> quit, kj::Own<kj::AsyncIoStream> stream, int& callCount) {
+  // Set up the server.
+  kj::UnixEventLoop eventLoop;
+  TwoPartyVatNetwork network(eventLoop, *stream, rpc::twoparty::Side::SERVER);
+  TestRestorer restorer(callCount);
+  auto server = makeRpcServer(network, restorer, eventLoop);
+
+  // Wait until quit promise is fulfilled.
+  eventLoop.wait(kj::mv(quit));
+}
+
+Capability::Client getPersistentCap(RpcSystem<rpc::twoparty::SturdyRefHostId>& client,
+                                    rpc::twoparty::Side side,
+                                    test::TestSturdyRefObjectId::Tag tag) {
+  // Create the SturdyRefHostId.
+  MallocMessageBuilder hostIdMessage(8);
+  auto hostId = hostIdMessage.initRoot<rpc::twoparty::SturdyRefHostId>();
+  hostId.setSide(side);
+
+  // Create the SturdyRefObjectId.
+  MallocMessageBuilder objectIdMessage(8);
+  objectIdMessage.initRoot<test::TestSturdyRefObjectId>().setTag(tag);
+
+  // Connect to the remote capability.
+  return client.restore(hostId, objectIdMessage.getRoot<ObjectPointer>());
+}
+
+using boost::asio::ip::tcp;
+int main()
+{
+  try
+  {
+    int callCount(0);
+    boost::asio::io_service io_service;
+
+    tcp::acceptor acceptor(io_service, tcp::endpoint(tcp::v4(), 49999));
+    tcp::socket socket(io_service);
+    acceptor.accept(socket);
+
+    kj::Own<AsyncIoStream> stream(AsyncIoStream::wrapFd(socket.native_handle()));
+    auto quitter = kj::newPromiseAndFulfiller<void>();
+    runServer(kj::mv(quitter.promise), kj::mv(stream), callCount);
+  }
+  catch (std::exception& e)
+  {
+    std::cerr << e.what() << std::endl;
+  }
+    return 0;
+}
--- a/examples/example_server.py
+++ b/examples/example_server.py
@@ -0,0 +1,39 @@
+import capnp
+import test_capnp
+
+import socket
+import traceback
+
+class Server:
+    def __init__(self, val=1):
+        self.val = val
+
+    def foo(self, context):
+        context.results.x = str(context.params.i * 5 + self.val)
+
+def restore(ref_id):
+    return test_capnp.TestInterface.new_server(Server(100))
+
+def example_server(host='localhost', port=49999):
+    backlog = 1 
+
+    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 
+    s.bind((host,port)) 
+    s.listen(backlog) 
+
+    loop = capnp.EventLoop()
+    while 1:
+        try:
+            (clientsocket, address) = s.accept()
+            stream = capnp.FdAsyncIoStream(clientsocket.fileno())
+            restorer = capnp.Restorer(test_capnp.TestSturdyRefObjectId, restore)
+            server = capnp.RpcServer(loop, stream, restorer)
+
+            waiter = capnp.PromiseFulfillerPair()
+            loop.wait(waiter)
+        except KeyboardInterrupt:
+            break
+        except:
+            traceback.print_exc()
+
+example_server()
--- a/examples/test.capnp
+++ b/examples/test.capnp
@@ -0,0 +1,613 @@
+# Copyright (c) 2013, Kenton Varda <temporal@gmail.com>
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice, this
+#    list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+#    this list of conditions and the following disclaimer in the documentation
+#    and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+@0xd508eebdc2dc42b8;
+
+using Cxx = import "c++.capnp";
+
+# Use a namespace likely to cause trouble if the generated code doesn't use fully-qualified
+# names for stuff in the capnproto namespace.
+$Cxx.namespace("capnproto_test::capnp::test");
+
+enum TestEnum {
+  foo @0;
+  bar @1;
+  baz @2;
+  qux @3;
+  quux @4;
+  corge @5;
+  grault @6;
+  garply @7;
+}
+
+struct TestAllTypes {
+  voidField      @0  : Void;
+  boolField      @1  : Bool;
+  int8Field      @2  : Int8;
+  int16Field     @3  : Int16;
+  int32Field     @4  : Int32;
+  int64Field     @5  : Int64;
+  uInt8Field     @6  : UInt8;
+  uInt16Field    @7  : UInt16;
+  uInt32Field    @8  : UInt32;
+  uInt64Field    @9  : UInt64;
+  float32Field   @10 : Float32;
+  float64Field   @11 : Float64;
+  textField      @12 : Text;
+  dataField      @13 : Data;
+  structField    @14 : TestAllTypes;
+  enumField      @15 : TestEnum;
+  interfaceField @16 : Void;  # TODO
+
+  voidList      @17 : List(Void);
+  boolList      @18 : List(Bool);
+  int8List      @19 : List(Int8);
+  int16List     @20 : List(Int16);
+  int32List     @21 : List(Int32);
+  int64List     @22 : List(Int64);
+  uInt8List     @23 : List(UInt8);
+  uInt16List    @24 : List(UInt16);
+  uInt32List    @25 : List(UInt32);
+  uInt64List    @26 : List(UInt64);
+  float32List   @27 : List(Float32);
+  float64List   @28 : List(Float64);
+  textList      @29 : List(Text);
+  dataList      @30 : List(Data);
+  structList    @31 : List(TestAllTypes);
+  enumList      @32 : List(TestEnum);
+  interfaceList @33 : List(Void);  # TODO
+}
+
+struct TestDefaults {
+  voidField      @0  : Void    = void;
+  boolField      @1  : Bool    = true;
+  int8Field      @2  : Int8    = -123;
+  int16Field     @3  : Int16   = -12345;
+  int32Field     @4  : Int32   = -12345678;
+  int64Field     @5  : Int64   = -123456789012345;
+  uInt8Field     @6  : UInt8   = 234;
+  uInt16Field    @7  : UInt16  = 45678;
+  uInt32Field    @8  : UInt32  = 3456789012;
+  uInt64Field    @9  : UInt64  = 12345678901234567890;
+  float32Field   @10 : Float32 = 1234.5;
+  float64Field   @11 : Float64 = -123e45;
+  textField      @12 : Text    = "foo";
+  dataField      @13 : Data    = "bar";
+  structField    @14 : TestAllTypes = (
+      voidField      = void,
+      boolField      = true,
+      int8Field      = -12,
+      int16Field     = 3456,
+      int32Field     = -78901234,
+      int64Field     = 56789012345678,
+      uInt8Field     = 90,
+      uInt16Field    = 1234,
+      uInt32Field    = 56789012,
+      uInt64Field    = 345678901234567890,
+      float32Field   = -1.25e-10,
+      float64Field   = 345,
+      textField      = "baz",
+      dataField      = "qux",
+      structField    = (
+          textField = "nested",
+          structField = (textField = "really nested")),
+      enumField      = baz,
+      # interfaceField can't have a default
+
+      voidList      = [void, void, void],
+      boolList      = [false, true, false, true, true],
+      int8List      = [12, -34, -0x80, 0x7f],
+      int16List     = [1234, -5678, -0x8000, 0x7fff],
+      int32List     = [12345678, -90123456, -0x80000000, 0x7fffffff],
+      int64List     = [123456789012345, -678901234567890, -0x8000000000000000, 0x7fffffffffffffff],
+      uInt8List     = [12, 34, 0, 0xff],
+      uInt16List    = [1234, 5678, 0, 0xffff],
+      uInt32List    = [12345678, 90123456, 0, 0xffffffff],
+      uInt64List    = [123456789012345, 678901234567890, 0, 0xffffffffffffffff],
+      float32List   = [0, 1234567, 1e37, -1e37, 1e-37, -1e-37],
+      float64List   = [0, 123456789012345, 1e306, -1e306, 1e-306, -1e-306],
+      textList      = ["quux", "corge", "grault"],
+      dataList      = ["garply", "waldo", "fred"],
+      structList    = [
+          (textField = "x structlist 1"),
+          (textField = "x structlist 2"),
+          (textField = "x structlist 3")],
+      enumList      = [qux, bar, grault]
+      # interfaceList can't have a default
+      );
+  enumField      @15 : TestEnum = corge;
+  interfaceField @16 : Void;  # TODO
+
+  voidList      @17 : List(Void)    = [void, void, void, void, void, void];
+  boolList      @18 : List(Bool)    = [true, false, false, true];
+  int8List      @19 : List(Int8)    = [111, -111];
+  int16List     @20 : List(Int16)   = [11111, -11111];
+  int32List     @21 : List(Int32)   = [111111111, -111111111];
+  int64List     @22 : List(Int64)   = [1111111111111111111, -1111111111111111111];
+  uInt8List     @23 : List(UInt8)   = [111, 222] ;
+  uInt16List    @24 : List(UInt16)  = [33333, 44444];
+  uInt32List    @25 : List(UInt32)  = [3333333333];
+  uInt64List    @26 : List(UInt64)  = [11111111111111111111];
+  float32List   @27 : List(Float32) = [5555.5, inf, -inf, nan];
+  float64List   @28 : List(Float64) = [7777.75, inf, -inf, nan];
+  textList      @29 : List(Text)    = ["plugh", "xyzzy", "thud"];
+  dataList      @30 : List(Data)    = ["oops", "exhausted", "rfc3092"];
+  structList    @31 : List(TestAllTypes) = [
+      (textField = "structlist 1"),
+      (textField = "structlist 2"),
+      (textField = "structlist 3")];
+  enumList      @32 : List(TestEnum) = [foo, garply];
+  interfaceList @33 : List(Void);  # TODO
+}
+
+struct TestObject {
+  objectField @0 :Object;
+
+  # Do not add any other fields here!  Some tests rely on objectField being the last pointer
+  # in the struct.
+}
+
+struct TestOutOfOrder {
+  foo @3 :Text;
+  bar @2 :Text;
+  baz @8 :Text;
+  qux @0 :Text;
+  quux @6 :Text;
+  corge @4 :Text;
+  grault @1 :Text;
+  garply @7 :Text;
+  waldo @5 :Text;
+}
+
+struct TestUnion {
+  union0 @0! :union {
+    # Pack union 0 under ideal conditions: there is no unused padding space prior to it.
+    u0f0s0  @4: Void;
+    u0f0s1  @5: Bool;
+    u0f0s8  @6: Int8;
+    u0f0s16 @7: Int16;
+    u0f0s32 @8: Int32;
+    u0f0s64 @9: Int64;
+    u0f0sp  @10: Text;
+
+    # Pack more stuff into union0 -- should go in same space.
+    u0f1s0  @11: Void;
+    u0f1s1  @12: Bool;
+    u0f1s8  @13: Int8;
+    u0f1s16 @14: Int16;
+    u0f1s32 @15: Int32;
+    u0f1s64 @16: Int64;
+    u0f1sp  @17: Text;
+  }
+
+  # Pack one bit in order to make pathological situation for union1.
+  bit0 @18: Bool;
+
+  union1 @1! :union {
+    # Pack pathologically bad case.  Each field takes up new space.
+    u1f0s0  @19: Void;
+    u1f0s1  @20: Bool;
+    u1f1s1  @21: Bool;
+    u1f0s8  @22: Int8;
+    u1f1s8  @23: Int8;
+    u1f0s16 @24: Int16;
+    u1f1s16 @25: Int16;
+    u1f0s32 @26: Int32;
+    u1f1s32 @27: Int32;
+    u1f0s64 @28: Int64;
+    u1f1s64 @29: Int64;
+    u1f0sp  @30: Text;
+    u1f1sp  @31: Text;
+
+    # Pack more stuff into union1 -- each should go into the same space as corresponding u1f0s*.
+    u1f2s0  @32: Void;
+    u1f2s1  @33: Bool;
+    u1f2s8  @34: Int8;
+    u1f2s16 @35: Int16;
+    u1f2s32 @36: Int32;
+    u1f2s64 @37: Int64;
+    u1f2sp  @38: Text;
+  }
+
+  # Fill in the rest of that bitfield from earlier.
+  bit2 @39: Bool;
+  bit3 @40: Bool;
+  bit4 @41: Bool;
+  bit5 @42: Bool;
+  bit6 @43: Bool;
+  bit7 @44: Bool;
+
+  # Interleave two unions to be really annoying.
+  # Also declare in reverse order to make sure union discriminant values are sorted by field number
+  # and not by declaration order.
+  union2 @2! :union {
+    u2f0s64 @54: Int64;
+    u2f0s32 @52: Int32;
+    u2f0s16 @50: Int16;
+    u2f0s8 @47: Int8;
+    u2f0s1 @45: Bool;
+  }
+
+  union3 @3! :union {
+    u3f0s64 @55: Int64;
+    u3f0s32 @53: Int32;
+    u3f0s16 @51: Int16;
+    u3f0s8 @48: Int8;
+    u3f0s1 @46: Bool;
+  }
+
+  byte0 @49: UInt8;
+}
+
+struct TestUnnamedUnion {
+  before @0 :Text;
+
+  union {
+    foo @1 :UInt16;
+    bar @3 :UInt32;
+  }
+
+  middle @2 :UInt16;
+
+  after @4 :Text;
+}
+
+struct TestUnionInUnion {
+  # There is no reason to ever do this.
+  outer :union {
+    inner :union {
+      foo @0 :Int32;
+      bar @1 :Int32;
+    }
+    baz @2 :Int32;
+  }
+}
+
+struct TestGroups {
+  groups :union {
+    foo :group {
+      corge @0 :Int32;
+      grault @2 :Int64;
+      garply @8 :Text;
+    }
+    bar :group {
+      corge @3 :Int32;
+      grault @4 :Text;
+      garply @5 :Int64;
+    }
+    baz :group {
+      corge @1 :Int32;
+      grault @6 :Text;
+      garply @7 :Text;
+    }
+  }
+}
+
+struct TestInterleavedGroups {
+  group1 :group {
+    foo @0 :UInt32;
+    bar @2 :UInt64;
+    union {
+      qux @4 :UInt16;
+      corge :group {
+        grault @6 :UInt64;
+        garply @8 :UInt16;
+        plugh @14 :Text;
+        xyzzy @16 :Text;
+      }
+
+      fred @12 :Text;
+    }
+
+    waldo @10 :Text;
+  }
+
+  group2 :group {
+    foo @1 :UInt32;
+    bar @3 :UInt64;
+    union {
+      qux @5 :UInt16;
+      corge :group {
+        grault @7 :UInt64;
+        garply @9 :UInt16;
+        plugh @15 :Text;
+        xyzzy @17 :Text;
+      }
+
+      fred @13 :Text;
+    }
+
+    waldo @11 :Text;
+  }
+}
+
+struct TestUnionDefaults {
+  s16s8s64s8Set @0 :TestUnion =
+      (union0 = (u0f0s16 = 321), union1 = (u1f0s8 = 123), union2 = (u2f0s64 = 12345678901234567),
+       union3 = (u3f0s8 = 55));
+  s0sps1s32Set @1 :TestUnion =
+      (union0 = (u0f1s0 = void), union1 = (u1f0sp = "foo"), union2 = (u2f0s1 = true),
+       union3 = (u3f0s32 = 12345678));
+
+  unnamed1 @2 :TestUnnamedUnion = (foo = 123);
+  unnamed2 @3 :TestUnnamedUnion = (bar = 321, before = "foo", after = "bar");
+}
+
+struct TestNestedTypes {
+  enum NestedEnum {
+    foo @0;
+    bar @1;
+  }
+
+  struct NestedStruct {
+    enum NestedEnum {
+      baz @0;
+      qux @1;
+      quux @2;
+    }
+
+    outerNestedEnum @0 :TestNestedTypes.NestedEnum = bar;
+    innerNestedEnum @1 :NestedEnum = quux;
+  }
+
+  nestedStruct @0 :NestedStruct;
+
+  outerNestedEnum @1 :NestedEnum = bar;
+  innerNestedEnum @2 :NestedStruct.NestedEnum = quux;
+}
+
+struct TestUsing {
+  using OuterNestedEnum = TestNestedTypes.NestedEnum;
+  using TestNestedTypes.NestedStruct.NestedEnum;
+
+  outerNestedEnum @1 :OuterNestedEnum = bar;
+  innerNestedEnum @0 :NestedEnum = quux;
+}
+
+struct TestLists {
+  # Small structs, when encoded as list, will be encoded as primitive lists rather than struct
+  # lists, to save space.
+  struct Struct0  { f @0 :Void; }
+  struct Struct1  { f @0 :Bool; }
+  struct Struct8  { f @0 :UInt8; }
+  struct Struct16 { f @0 :UInt16; }
+  struct Struct32 { f @0 :UInt32; }
+  struct Struct64 { f @0 :UInt64; }
+  struct StructP  { f @0 :Text; }
+
+  # Versions of the above which cannot be encoded as primitive lists.
+  struct Struct0c  { f @0 :Void; pad @1 :Text; }
+  struct Struct1c  { f @0 :Bool; pad @1 :Text; }
+  struct Struct8c  { f @0 :UInt8; pad @1 :Text; }
+  struct Struct16c { f @0 :UInt16; pad @1 :Text; }
+  struct Struct32c { f @0 :UInt32; pad @1 :Text; }
+  struct Struct64c { f @0 :UInt64; pad @1 :Text; }
+  struct StructPc  { f @0 :Text; pad @1 :UInt64; }
+
+  list0  @0 :List(Struct0);
+  list1  @1 :List(Struct1);
+  list8  @2 :List(Struct8);
+  list16 @3 :List(Struct16);
+  list32 @4 :List(Struct32);
+  list64 @5 :List(Struct64);
+  listP  @6 :List(StructP);
+
+  int32ListList @7 :List(List(Int32));
+  textListList @8 :List(List(Text));
+  structListList @9 :List(List(TestAllTypes));
+}
+
+struct TestFieldZeroIsBit {
+  bit @0 :Bool;
+  secondBit @1 :Bool = true;
+  thirdField @2 :UInt8 = 123;
+}
+
+struct TestListDefaults {
+  lists @0 :TestLists = (
+      list0  = [(f = void), (f = void)],
+      list1  = [(f = true), (f = false), (f = true), (f = true)],
+      list8  = [(f = 123), (f = 45)],
+      list16 = [(f = 12345), (f = 6789)],
+      list32 = [(f = 123456789), (f = 234567890)],
+      list64 = [(f = 1234567890123456), (f = 2345678901234567)],
+      listP  = [(f = "foo"), (f = "bar")],
+      int32ListList = [[1, 2, 3], [4, 5], [12341234]],
+      textListList = [["foo", "bar"], ["baz"], ["qux", "corge"]],
+      structListList = [[(int32Field = 123), (int32Field = 456)], [(int32Field = 789)]]);
+}
+
+struct TestLateUnion {
+  # Test what happens if the unions are not the first ordinals in the struct.  At one point this
+  # was broken for the dynamic API.
+
+  foo @0 :Int32;
+  bar @1 :Text;
+  baz @2 :Int16;
+
+  theUnion @3! :union {
+    qux @4 :Text;
+    corge @5 :List(Int32);
+    grault @6 :Float32;
+  }
+
+  anotherUnion @7! :union {
+    qux @8 :Text;
+    corge @9 :List(Int32);
+    grault @10 :Float32;
+  }
+}
+
+struct TestOldVersion {
+  # A subset of TestNewVersion.
+  old1 @0 :Int64;
+  old2 @1 :Text;
+  old3 @2 :TestOldVersion;
+}
+
+struct TestNewVersion {
+  # A superset of TestOldVersion.
+  old1 @0 :Int64;
+  old2 @1 :Text;
+  old3 @2 :TestNewVersion;
+  new1 @3 :Int64 = 987;
+  new2 @4 :Text = "baz";
+}
+
+struct TestStructUnion {
+  un @0! :union {
+    allTypes @1 :TestAllTypes;
+    object @2 :TestObject;
+  }
+}
+
+struct TestEmptyStruct {}
+
+struct TestConstants {
+  const voidConst      :Void    = void;
+  const boolConst      :Bool    = true;
+  const int8Const      :Int8    = -123;
+  const int16Const     :Int16   = -12345;
+  const int32Const     :Int32   = -12345678;
+  const int64Const     :Int64   = -123456789012345;
+  const uint8Const     :UInt8   = 234;
+  const uint16Const    :UInt16  = 45678;
+  const uint32Const    :UInt32  = 3456789012;
+  const uint64Const    :UInt64  = 12345678901234567890;
+  const float32Const   :Float32 = 1234.5;
+  const float64Const   :Float64 = -123e45;
+  const textConst      :Text    = "foo";
+  const dataConst      :Data    = "bar";
+  const structConst    :TestAllTypes = (
+      voidField      = void,
+      boolField      = true,
+      int8Field      = -12,
+      int16Field     = 3456,
+      int32Field     = -78901234,
+      int64Field     = 56789012345678,
+      uInt8Field     = 90,
+      uInt16Field    = 1234,
+      uInt32Field    = 56789012,
+      uInt64Field    = 345678901234567890,
+      float32Field   = -1.25e-10,
+      float64Field   = 345,
+      textField      = "baz",
+      dataField      = "qux",
+      structField    = (
+          textField = "nested",
+          structField = (textField = "really nested")),
+      enumField      = baz,
+      # interfaceField can't have a default
+
+      voidList      = [void, void, void],
+      boolList      = [false, true, false, true, true],
+      int8List      = [12, -34, -0x80, 0x7f],
+      int16List     = [1234, -5678, -0x8000, 0x7fff],
+      int32List     = [12345678, -90123456, -0x80000000, 0x7fffffff],
+      int64List     = [123456789012345, -678901234567890, -0x8000000000000000, 0x7fffffffffffffff],
+      uInt8List     = [12, 34, 0, 0xff],
+      uInt16List    = [1234, 5678, 0, 0xffff],
+      uInt32List    = [12345678, 90123456, 0, 0xffffffff],
+      uInt64List    = [123456789012345, 678901234567890, 0, 0xffffffffffffffff],
+      float32List   = [0, 1234567, 1e37, -1e37, 1e-37, -1e-37],
+      float64List   = [0, 123456789012345, 1e306, -1e306, 1e-306, -1e-306],
+      textList      = ["quux", "corge", "grault"],
+      dataList      = ["garply", "waldo", "fred"],
+      structList    = [
+          (textField = "x structlist 1"),
+          (textField = "x structlist 2"),
+          (textField = "x structlist 3")],
+      enumList      = [qux, bar, grault]
+      # interfaceList can't have a default
+      );
+  const enumConst      :TestEnum = corge;
+
+  const voidListConst      :List(Void)    = [void, void, void, void, void, void];
+  const boolListConst      :List(Bool)    = [true, false, false, true];
+  const int8ListConst      :List(Int8)    = [111, -111];
+  const int16ListConst     :List(Int16)   = [11111, -11111];
+  const int32ListConst     :List(Int32)   = [111111111, -111111111];
+  const int64ListConst     :List(Int64)   = [1111111111111111111, -1111111111111111111];
+  const uint8ListConst     :List(UInt8)   = [111, 222] ;
+  const uint16ListConst    :List(UInt16)  = [33333, 44444];
+  const uint32ListConst    :List(UInt32)  = [3333333333];
+  const uint64ListConst    :List(UInt64)  = [11111111111111111111];
+  const float32ListConst   :List(Float32) = [5555.5, inf, -inf, nan];
+  const float64ListConst   :List(Float64) = [7777.75, inf, -inf, nan];
+  const textListConst      :List(Text)    = ["plugh", "xyzzy", "thud"];
+  const dataListConst      :List(Data)    = ["oops", "exhausted", "rfc3092"];
+  const structListConst    :List(TestAllTypes) = [
+      (textField = "structlist 1"),
+      (textField = "structlist 2"),
+      (textField = "structlist 3")];
+  const enumListConst      :List(TestEnum) = [foo, garply];
+}
+
+const globalInt :UInt32 = 12345;
+const globalText :Text = "foobar";
+const globalStruct :TestAllTypes = (int32Field = 54321);
+const derivedConstant :TestAllTypes = (
+    uInt32Field = .globalInt,
+    textField = TestConstants.textConst,
+    structField = TestConstants.structConst,
+    int16List = TestConstants.int16ListConst,
+    structList = TestConstants.structListConst);
+
+interface TestInterface {
+  foo @0 (i :UInt32, j :Bool) -> (x: Text);
+  bar @1 () -> ();
+  baz @2 (s: TestAllTypes);
+}
+
+interface TestExtends extends(TestInterface) {
+  qux @0 ();
+  corge @1 TestAllTypes -> ();
+  grault @2 () -> TestAllTypes;
+}
+
+interface TestPipeline {
+  getCap @0 (n: UInt32, inCap :TestInterface) -> (s: Text, outBox :Box);
+  testPointers @1 (cap :TestInterface, obj :Object, list :List(TestInterface)) -> ();
+
+  struct Box {
+    cap @0 :TestInterface;
+  }
+}
+
+struct TestSturdyRefHostId {
+  host @0 :Text;
+}
+
+struct TestSturdyRefObjectId {
+  tag @0 :Tag;
+  enum Tag {
+    testInterface @0;
+    testExtends @1;
+    testPipeline @2;
+  }
+}
+
+struct TestProvisionId {}
+struct TestRecipientId {}
+struct TestThirdPartyCapId {}
+struct TestJoinAnswer {}
--- a/examples/test.capnp.c++
+++ b/examples/test.capnp.c++
--- a/examples/test.capnp.h
+++ b/examples/test.capnp.h
--- a/scripts/capnp-json.py
+++ b/scripts/capnp-json.py
@@ -0,0 +1,44 @@
+#!/usr/bin/env python
+
+import argparse
+import sys
+import json
+import capnp
+
+def parse_args():
+    parser = argparse.ArgumentParser()
+    parser.add_argument("command")
+    parser.add_argument("schema_file")
+    parser.add_argument("struct_name")
+    parser.add_argument("-d", "--defaults", help="include default values in json output", action="store_true")
+
+    return parser.parse_args()
+
+def encode(schema_file, struct_name, **kwargs):
+    schema = capnp.load(schema_file)
+
+    struct_schema = getattr(schema, struct_name)
+    
+    struct_dict = json.load(sys.stdin)
+    struct = struct_schema.from_dict(struct_dict)
+
+    struct.write(sys.stdout)
+
+def decode(schema_file, struct_name, defaults):
+    schema = capnp.load(schema_file)
+
+    struct_schema = getattr(schema, struct_name)
+    struct = struct_schema.read(sys.stdin)
+    
+    json.dump(struct.to_dict(defaults), sys.stdout)
+
+def main():
+    args = parse_args()
+
+    command = args.command
+    kwargs = vars(args)
+    del kwargs['command']
+
+    globals()[command](**kwargs) # hacky way to get defined functions, and call function with name=command
+
+main()
--- a/setup.py
+++ b/setup.py
@@ -11,15 +11,15 @@ if Cython.__version__ < '0.19.1':
 import pkg_resources
 setuptools_version = pkg_resources.get_distribution("setuptools").version
 if setuptools_version < '0.8':
-    raise RuntimeError('Old setuptools installed (%s). Please run `pip install -U setuptools`. Running `pip install capnp` will not work alone, since setuptools needs to be upgraded before installing anything else.' % setuptools_version)
+    raise RuntimeError('Old setuptools installed (%s). Please run `pip install -U setuptools`. Running `pip install pycapnp` will not work alone, since setuptools needs to be upgraded before installing anything else.' % setuptools_version)

 from distutils.core import setup
 import os

 MAJOR = 0
-MINOR = 3
-MICRO = 18
-VERSION = '%d.%d.%d' % (MAJOR, MINOR, MICRO)
+MINOR = 4
+MICRO = 0
+VERSION = '%d.%d.%d-dev' % (MAJOR, MINOR, MICRO)

 def write_version_py(filename=None):
    cnt = """\
@@ -54,7 +54,7 @@ setup(
        'cython > 0.19',
        'setuptools >= 0.8'],
    # PyPi info
-    description='A cython wrapping of the C++ capnproto library',
+    description="A cython wrapping of the C++ Cap'n Proto library",
    long_description=long_description,
    license='BSD',
    author="Jason Paryani",
--- a/test/all-types.txt
+++ b/test/all-types.txt
@@ -1,4 +1,5 @@
-( boolField = true,
+( voidField = void,
+  boolField = true,
  int8Field = -123,
  int16Field = -12345,
  int32Field = -12345678,
@@ -12,6 +13,7 @@
  textField = "foo",
  dataField = "bar",
  structField = (
+    voidField = void,
    boolField = true,
    int8Field = -12,
    int16Field = 3456,
@@ -26,10 +28,39 @@
    textField = "baz",
    dataField = "qux",
    structField = (
+      voidField = void,
+      boolField = false,
+      int8Field = 0,
+      int16Field = 0,
+      int32Field = 0,
+      int64Field = 0,
+      uInt8Field = 0,
+      uInt16Field = 0,
+      uInt32Field = 0,
+      uInt64Field = 0,
+      float32Field = 0,
+      float64Field = 0,
      textField = "nested",
      structField = (
-        textField = "really nested" ) ),
+        voidField = void,
+        boolField = false,
+        int8Field = 0,
+        int16Field = 0,
+        int32Field = 0,
+        int64Field = 0,
+        uInt8Field = 0,
+        uInt16Field = 0,
+        uInt32Field = 0,
+        uInt64Field = 0,
+        float32Field = 0,
+        float64Field = 0,
+        textField = "really nested",
+        enumField = foo,
+        interfaceField = void ),
+      enumField = foo,
+      interfaceField = void ),
    enumField = baz,
+    interfaceField = void,
    voidList = [void, void, void],
    boolList = [false, true, false, true, true],
    int8List = [12, -34, -128, 127],
@@ -45,11 +76,54 @@
    textList = ["quux", "corge", "grault"],
    dataList = ["garply", "waldo", "fred"],
    structList = [
-      ( textField = "x structlist 1" ),
-      ( textField = "x structlist 2" ),
-      ( textField = "x structlist 3" ) ],
+      ( voidField = void,
+        boolField = false,
+        int8Field = 0,
+        int16Field = 0,
+        int32Field = 0,
+        int64Field = 0,
+        uInt8Field = 0,
+        uInt16Field = 0,
+        uInt32Field = 0,
+        uInt64Field = 0,
+        float32Field = 0,
+        float64Field = 0,
+        textField = "x structlist 1",
+        enumField = foo,
+        interfaceField = void ),
+      ( voidField = void,
+        boolField = false,
+        int8Field = 0,
+        int16Field = 0,
+        int32Field = 0,
+        int64Field = 0,
+        uInt8Field = 0,
+        uInt16Field = 0,
+        uInt32Field = 0,
+        uInt64Field = 0,
+        float32Field = 0,
+        float64Field = 0,
+        textField = "x structlist 2",
+        enumField = foo,
+        interfaceField = void ),
+      ( voidField = void,
+        boolField = false,
+        int8Field = 0,
+        int16Field = 0,
+        int32Field = 0,
+        int64Field = 0,
+        uInt8Field = 0,
+        uInt16Field = 0,
+        uInt32Field = 0,
+        uInt64Field = 0,
+        float32Field = 0,
+        float64Field = 0,
+        textField = "x structlist 3",
+        enumField = foo,
+        interfaceField = void ) ],
    enumList = [qux, bar, grault] ),
  enumField = corge,
+  interfaceField = void,
  voidList = [void, void, void, void, void, void],
  boolList = [true, false, false, true],
  int8List = [111, -111],
@@ -65,7 +139,49 @@
  textList = ["plugh", "xyzzy", "thud"],
  dataList = ["oops", "exhausted", "rfc3092"],
  structList = [
-    ( textField = "structlist 1" ),
-    ( textField = "structlist 2" ),
-    ( textField = "structlist 3" ) ],
+    ( voidField = void,
+      boolField = false,
+      int8Field = 0,
+      int16Field = 0,
+      int32Field = 0,
+      int64Field = 0,
+      uInt8Field = 0,
+      uInt16Field = 0,
+      uInt32Field = 0,
+      uInt64Field = 0,
+      float32Field = 0,
+      float64Field = 0,
+      textField = "structlist 1",
+      enumField = foo,
+      interfaceField = void ),
+    ( voidField = void,
+      boolField = false,
+      int8Field = 0,
+      int16Field = 0,
+      int32Field = 0,
+      int64Field = 0,
+      uInt8Field = 0,
+      uInt16Field = 0,
+      uInt32Field = 0,
+      uInt64Field = 0,
+      float32Field = 0,
+      float64Field = 0,
+      textField = "structlist 2",
+      enumField = foo,
+      interfaceField = void ),
+    ( voidField = void,
+      boolField = false,
+      int8Field = 0,
+      int16Field = 0,
+      int32Field = 0,
+      int64Field = 0,
+      uInt8Field = 0,
+      uInt16Field = 0,
+      uInt32Field = 0,
+      uInt64Field = 0,
+      float32Field = 0,
+      float64Field = 0,
+      textField = "structlist 3",
+      enumField = foo,
+      interfaceField = void ) ],
  enumList = [foo, garply] )
--- a/test/test_capability.capnp
+++ b/test/test_capability.capnp
@@ -0,0 +1,56 @@
+# Copyright (c) 2013, Kenton Varda <temporal@gmail.com>
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice, this
+#    list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+#    this list of conditions and the following disclaimer in the documentation
+#    and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+@0xd508eefec2dc42b8;
+
+interface TestInterface {
+  foo @0 (i :UInt32, j :Bool) -> (x: Text);
+  bar @1 () -> ();
+  # baz @2 (s: TestAllTypes);
+}
+
+interface TestExtends extends(TestInterface) {
+  qux @0 ();
+}
+
+interface TestPipeline {
+  getCap @0 (n: UInt32, inCap :TestInterface) -> (s: Text, outBox :Box);
+  testPointers @1 (cap :TestInterface, obj :Object, list :List(TestInterface)) -> ();
+
+  struct Box {
+    cap @0 :TestInterface;
+  }
+}
+
+struct TestSturdyRefHostId {
+  host @0 :Text;
+}
+
+struct TestSturdyRefObjectId {
+  tag @0 :Tag;
+  enum Tag {
+    testInterface @0;
+    testExtends @1;
+    testPipeline @2;
+  }
+}
--- a/test/test_capability.py
+++ b/test/test_capability.py
@@ -0,0 +1,167 @@
+import pytest
+import capnp
+import os
+
+this_dir = os.path.dirname(__file__)
+
+@pytest.fixture
+def capability():
+     return capnp.load(os.path.join(this_dir, 'test_capability.capnp'))
+
+class Server:
+    def __init__(self, val=1):
+        self.val = val
+
+    def foo(self, context):
+        context.results.x = str(context.params.i * 5 + self.val)
+
+class PipelineServer:
+    def getCap(self, context):
+        def _then(response):
+            context.results.s = response.x + '_foo'
+            context.results.outBox.cap = capability().TestInterface.new_server(Server(100))
+
+        return context.params.inCap.foo(i=context.params.n).then(_then)
+
+def test_client(capability):
+    loop = capnp.EventLoop()
+
+    client = capability.TestInterface.new_client(Server(), loop)
+    
+    req = client._request('foo')
+    req.i = 5
+
+    remote = req.send()
+    response = loop.wait(remote)
+
+    assert response.x == '26'
+    
+    req = client.foo_request()
+    req.i = 5
+
+    remote = req.send()
+    response = loop.wait(remote)
+
+    assert response.x == '26'
+
+    with pytest.raises(ValueError):
+        client.foo2_request()
+
+    req = client.foo_request()
+
+    with pytest.raises(ValueError):
+        req.i = 'foo'
+
+    req = client.foo_request()
+
+    with pytest.raises(ValueError):
+        req.baz = 1
+
+def test_simple_client(capability):
+    loop = capnp.EventLoop()
+
+    client = capability.TestInterface.new_client(Server(), loop)
+    
+    remote = client._send('foo', i=5)
+    response = loop.wait(remote)
+
+    assert response.x == '26'
+
+    
+    remote = client.foo(i=5)
+    response = loop.wait(remote)
+
+    assert response.x == '26'
+
+    with pytest.raises(ValueError):
+        remote = client.foo(i='foo')
+
+    with pytest.raises(ValueError):
+        remote = client.foo2(i=5)
+
+    with pytest.raises(ValueError):
+        remote = client.foo(baz=5)
+
+def test_pipeline(capability):
+    loop = capnp.EventLoop()
+
+    client = capability.TestPipeline.new_client(PipelineServer(), loop)
+    foo_client = capability.TestInterface.new_client(Server(), loop)
+
+    remote = client.getCap(n=5, inCap=foo_client)
+
+    outCap = remote.outBox.cap
+    pipelinePromise = outCap.foo(i=10)
+
+    response = loop.wait(pipelinePromise)
+    assert response.x == '150'
+
+    response = loop.wait(remote)
+    assert response.s == '26_foo'
+
+class BadServer:
+    def __init__(self, val=1):
+        self.val = val
+
+    def foo(self, context):
+        context.results.x = str(context.params.i * 5 + self.val)
+        context.results.x2 = 5 # raises exception
+
+def test_exception_client(capability):
+    loop = capnp.EventLoop()
+
+    client = capability.TestInterface.new_client(BadServer(), loop)
+    
+    remote = client._send('foo', i=5)
+    with pytest.raises(capnp.KjException):
+        loop.wait(remote)
+
+class BadPipelineServer:
+    def getCap(self, context):
+        def _then(response):
+            context.results.s = response.x + '_foo'
+            context.results.outBox.cap = capability().TestInterface.new_server(Server(100))
+        def _error(error):
+            raise Exception('test was a success')
+
+        return context.params.inCap.foo(i=context.params.n).then(_then, _error)
+
+def test_exception_chain(capability):
+    loop = capnp.EventLoop()
+
+    client = capability.TestPipeline.new_client(BadPipelineServer(), loop)
+    foo_client = capability.TestInterface.new_client(BadServer(), loop)
+
+    remote = client.getCap(n=5, inCap=foo_client)
+
+    try:
+        loop.wait(remote)
+    except Exception as e:
+        assert 'test was a success' in str(e)
+
+def test_pipeline_exception(capability):
+    loop = capnp.EventLoop()
+
+    client = capability.TestPipeline.new_client(BadPipelineServer(), loop)
+    foo_client = capability.TestInterface.new_client(BadServer(), loop)
+
+    remote = client.getCap(n=5, inCap=foo_client)
+
+    outCap = remote.outBox.cap
+    pipelinePromise = outCap.foo(i=10)
+
+    with pytest.raises(Exception):
+        loop.wait(pipelinePromise)
+
+    with pytest.raises(Exception):
+        loop.wait(remote)
+
+def test_casting(capability):
+    loop = capnp.EventLoop()
+
+    client = capability.TestExtends.new_client(Server(), loop)
+    client2 = client.upcast(capability.TestInterface)
+    client3 = client2.cast_as(capability.TestInterface)
+
+    with pytest.raises(Exception):
+        client.upcast(capability.TestPipeline)
--- a/test/test_rpc.py
+++ b/test/test_rpc.py
@@ -0,0 +1,40 @@
+import pytest
+import capnp
+import os
+import socket
+
+this_dir = os.path.dirname(__file__)
+
+@pytest.fixture
+def capability():
+     return capnp.load(os.path.join(this_dir, 'test_capability.capnp'))
+
+class Server:
+    def __init__(self, val=1):
+        self.val = val
+
+    def foo(self, context):
+        context.results.x = str(context.params.i * 5 + self.val)
+
+def test_simple_rpc(capability):
+    def _restore(ref_id):
+        return capability.TestInterface.new_server(Server(100))
+
+    loop = capnp.EventLoop()
+
+    read, write = socket.socketpair(socket.AF_UNIX)
+    read_stream = capnp.FdAsyncIoStream(read.fileno())
+    write_stream = capnp.FdAsyncIoStream(write.fileno())
+
+    restorer = capnp.Restorer(capability.TestSturdyRefObjectId, _restore)
+    server = capnp.RpcServer(loop, write_stream, restorer)
+    client = capnp.RpcClient(loop, read_stream)
+
+    ref = capability.TestSturdyRefObjectId.new_message()
+    cap = client.restore(ref)
+    cap = cap.cast_as(capability.TestInterface)
+
+    remote = cap.foo(i=5)
+    response = loop.wait(remote)
+
+    assert response.x == '125'