fix c api

include/tvm/base.h

@@ -24,9 +24,9 @@ class BinaryOp;
 
 /*! \brief list of all supported data types */
 enum DataType {
-  kUnknown,
-  kInt32,
-  kFloat32
+  kUnknown = 0,
+  kInt32 = 1,
+  kFloat32 = 2
 };
 
 /*!

include/tvm/expr_node.h

@@ -27,6 +27,7 @@ class VarNode : public ExprNode {
   }
   void VisitAttrs(AttrVisitor* visitor) override {
     visitor->Visit("name", &name);
+    visitor->Visit("dtype", &dtype_);
   }
 };
 

python/tvm/cpp/_ctypes/_api.py

@@ -25,7 +25,26 @@ kDouble = 2
 kStr = 3
 kNodeHandle = 4
 
-RET_SWITCH = None
+
+def _type_key(handle):
+    ret_val = ArgVariant()
+    ret_typeid = ctypes.c_int()
+    check_call(_LIB.TVMNodeGetAttr(
+        handle, c_str("type_key"),
+        ctypes.byref(ret_val), ctypes.byref(ret_typeid)))
+    return py_str(ret_val.v_str)
+
+NODE_TYPE = {
+}
+
+RET_SWITCH = {
+    kNull: lambda x: None,
+    kLong: lambda x: x.v_long,
+    kDouble: lambda x: x.v_double,
+    kStr: lambda x: py_str(x.v_str),
+    kNodeHandle: lambda x: NODE_TYPE.get(_type_key(x), NodeBase)(x.v_handle)
+}
+
 
 class NodeBase(object):
     """Symbol is symbolic graph."""
@@ -50,27 +69,8 @@ class NodeBase(object):
         check_call(_LIB.TVMNodeGetAttr(
             self.handle, c_str(name),
             ctypes.byref(ret_val), ctypes.byref(ret_typeid)))
-        ret = RET_SWITCH[ret_typeid.value](ret_val)
-
-
-def _type_key(handle):
-    ret_val = ArgVariant()
-    ret_typeid = ctypes.c_int()
-    check_call(_LIB.TVMNodeGetAttr(
-        handle, c_str("type_key"),
-        ctypes.byref(ret_val), ctypes.byref(ret_typeid)))
-    return py_str(ret_val.v_str)
-
-NODE_TYPE = {
-}
+        return RET_SWITCH[ret_typeid.value](ret_val)
 
-RET_SWITCH = {
-    kNull: lambda x: None,
-    kLong: lambda x: x.v_long.value,
-    kDouble: lambda x: x.v_double.value,
-    kStr: lambda x: py_str(x.v_str),
-    kNodeHandle: lambda x: NODE_TYPE.get(_type_key(x), NodeBase)(x.v_handle)
-}
 
 def _push_arg(arg):
     a = ArgVariant()

python/tvm/cpp/function.py

 from ._ctypes._api import _init_function_module
 import _function_internal
 
+int32 = 1
+float32 = 2
+
+def Var(name="tindex", dtype=int32):
+    """Create a new variable with specified name and dtype
+
+    Parameters
+    ----------
+    name : str
+        The name
+
+    dtype : int
+        The data type
+    """
+    return _function_internal._Var(name, dtype)
+
+
 _init_function_module("tvm.cpp")

src/c_api/c_api_function.cc

@@ -16,9 +16,10 @@ namespace tvm {
 using ArgStack = const std::vector<APIVariantValue>;
 using RetValue = APIVariantValue;
 
-TVM_REGISTER_API(Var)
+TVM_REGISTER_API(_Var)
 .set_body([](const ArgStack& args,  RetValue *ret) {
-    *ret = Var(args.at(0), static_cast<DataType>(static_cast<int>(args.at(1))));
+    *ret = Var(args.at(0),
+               static_cast<DataType>(static_cast<int>(args.at(1))));
   })
 .add_argument("name", "str", "name of the var")
 .add_argument("dtype", "int", "data type of var");

tests/python/test_cpp.py

 from tvm import cpp as tvm
 
 def test_basic():
-    a = tvm.Var('a', 0)
-    b = tvm.Var('b', 0)
+    a = tvm.Var('a')
+    b = tvm.Var('b')
     z = tvm.max(a, b)
     assert tvm.format_str(z) == 'max(%s, %s)' % (a.name, b.name)