From c6250962e68021eef5f67761c5302ecc4aa05236 Mon Sep 17 00:00:00 2001
From: Jason Paryani <github@jparyani.com>
Date: Sun, 25 Aug 2013 17:07:08 -0700
Subject: [PATCH] Add handling of constants in schemas

---
 capnp/capnp.pyx            | 19 ++++++++++++++++---
 capnp/capnp_cpp.pxd        |  4 ++++
 capnp/schema_cpp.pxd       | 12 ++++++++++++
 examples/addressbook.capnp |  2 ++
 4 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/capnp/capnp.pyx b/capnp/capnp.pyx
index fab0831..e219fa6 100644
--- a/capnp/capnp.pyx
+++ b/capnp/capnp.pyx
@@ -87,6 +87,12 @@ cdef class _NodeReader:
     property nestedNodes:
         def __get__(self):
             return _List_NestedNode_Reader()._init(self.thisptr.getNestedNodes())
+    property isStruct:
+        def __get__(self):
+            return self.thisptr.isStruct()
+    property isConst:
+        def __get__(self):
+            return self.thisptr.isConst()
 
 cdef class _NestedNodeReader:
     cdef C_Node.NestedNode.Reader thisptr
@@ -364,6 +370,9 @@ cdef class Schema:
         self.thisptr = other
         return self
 
+    cpdef asConstValue(self):
+        return _DynamicValueReader()._init(<C_DynamicValue.Reader>self.thisptr.asConst(), self).toPython()
+
     cpdef asStruct(self):
         return StructSchema()._init(self.thisptr.asStruct())
 
@@ -385,6 +394,9 @@ cdef class ParsedSchema:
         self.thisptr = other
         return self
 
+    cpdef asConstValue(self):
+        return _DynamicValueReader()._init(<C_DynamicValue.Reader>self.thisptr.asConst(), self).toPython()
+
     cpdef asStruct(self):
         return StructSchema()._init(self.thisptr.asStruct())
 
@@ -506,10 +518,11 @@ def _load(nodeSchema, module):
         module.__dict__[node.name] = local_module
 
         schema = nodeSchema.getNested(node.name)
-        try:
+        proto = schema.getProto()
+        if proto.isStruct:
             local_module.Schema = schema.asStruct()
-        except:
-            pass
+        elif proto.isConst:
+            module.__dict__[node.name] = schema.asConstValue()
 
         _load(schema, local_module)
 
diff --git a/capnp/capnp_cpp.pxd b/capnp/capnp_cpp.pxd
index 4ed5917..efa3f3a 100644
--- a/capnp/capnp_cpp.pxd
+++ b/capnp/capnp_cpp.pxd
@@ -29,6 +29,7 @@ cdef extern from "capnp/schema.h" namespace " ::capnp":
         Node.Reader getProto() except +
         StructSchema asStruct() except +
         EnumSchema asEnum() except +
+        ConstSchema asConst() except +
         Schema getDependency(uint64_t id) except +
         #InterfaceSchema asInterface() const;
 
@@ -64,6 +65,9 @@ cdef extern from "capnp/schema.h" namespace " ::capnp":
         Enumerant getEnumerantByName(char * name)
         Node.Reader getProto()
 
+    cdef cppclass ConstSchema:
+        pass
+
 cdef extern from "capnp/schema-loader.h" namespace " ::capnp":
     cdef cppclass SchemaLoader:
         SchemaLoader()
diff --git a/capnp/schema_cpp.pxd b/capnp/schema_cpp.pxd
index 41157cf..c779541 100644
--- a/capnp/schema_cpp.pxd
+++ b/capnp/schema_cpp.pxd
@@ -438,6 +438,12 @@ cdef extern from "capnp/schema.capnp.h" namespace " ::capnp::schema":
             UInt64 getScopeId()
             List[Node.Node.NestedNode].Reader getNestedNodes()
             UInt64 getId()
+            bint isFile()
+            bint isStruct()
+            bint isEnum()
+            bint isInterface()
+            bint isConst()
+            bint isAnnotation()
         cppclass Builder:
             
             Node.Body getBody()
@@ -452,6 +458,12 @@ cdef extern from "capnp/schema.capnp.h" namespace " ::capnp::schema":
             List[Node.Node.NestedNode].Builder initNestedNodes(int)
             UInt64 getId()
             void setId(UInt64)
+            bint isFile()
+            bint isStruct()
+            bint isEnum()
+            bint isInterface()
+            bint isConst()
+            bint isAnnotation()
     cdef cppclass AnnotationNode:
 
     
diff --git a/examples/addressbook.capnp b/examples/addressbook.capnp
index 02e626a..e1cd77c 100644
--- a/examples/addressbook.capnp
+++ b/examples/addressbook.capnp
@@ -1,5 +1,7 @@
 @0x934efea7f017fff0;
 
+const qux :UInt32 = 123;
+
 struct Person {
   id @0 :UInt32;
   name @1 :Text;