Merge pull request #90 from jermainewang/cpp

[GraphIndex] Graph index and many related changes

python/dgl/__init__.py

-from .base import ALL
-
-from .batch import batch, unbatch
-
-from .context import cpu, gpu
+from . import backend
+from . import data
+from . import function
+from . import nn
 
-from .graph import DGLGraph, __MSG__, __REPR__
+from ._ffi.runtime_ctypes import TypeCode
+from ._ffi.function import register_func, get_global_func, list_global_func_names, extract_ext_funcs
+from ._ffi.base import DGLError, __version__
 
+from .base import ALL
+from .batched_graph import *
+from .graph import DGLGraph
 from .subgraph import DGLSubGraph
-
-from .generator import *

python/dgl/_ffi/README.md

+# C API and runtime
+
+Borrowed and adapted from TVM project.

python/dgl/_ffi/_ctypes/__init__.py

+"""ctypes specific implementation of FFI"""

python/dgl/_ffi/_cy2/__init__.py

+"""cython2 namespace"""

python/dgl/_ffi/_cy3/__init__.py

+"""cython3 namespace"""