Merge pull request apache#35 from vchuravy/vc/symbol_attr

basic interface for setting and getting attributes

src/symbolic-node.jl

@@ -122,6 +122,35 @@ function get_internals(self :: SymbolicNode)
   return SymbolicNode(MX_SymbolHandle(ref_hdr[]))
 end
 
+#=doc
+.. function:: get_attr(self :: SymbolicNode, key :: Symbol)
+
+   Get attribute attached to this :class:`SymbolicNode` belonging to key.
+=#
+function get_attr(self :: SymbolicNode, key :: Symbol)
+  key_s = bytestring(string(key))
+  ref_out = Ref{Cstring}()
+  ref_success = Ref{Cint}(-1)
+  @mxcall(:MXSymbolGetAttr, (MX_handle, Cstring, Ref{Cstring}, Ref{Cint}), self, key_s, ref_out, ref_success)
+  if ref_success[] == 1
+    return bytestring(ref_out[])
+  else
+    throw(KeyError(key))
+  end
+end
+
+#=doc
+.. function:: set_attr(self:: SymbolicNode, key :: Symbol, value :: AbstractString)
+
+   Set the attribute key to value for this :class:`SymbolicNode`.
+=#
+function set_attr(self :: SymbolicNode, key :: Symbol, value :: AbstractString)
+  key_s = bytestring(string(key))
+  value_s = bytestring(value)
+
+  @mxcall(:MXSymbolSetAttr, (MX_handle, Cstring, Cstring), self, key_s, value_s)
+end
+
 #=doc
 .. function:: Variable(name :: Union{Base.Symbol, AbstractString})
 

test/unittest/symbolic-node.jl

@@ -81,6 +81,14 @@ function test_saveload()
   rm(fname)
 end
 
+function test_attrs()
+  info("SymbolicNode::Attributes")
+
+  data = mx.Variable(:data)
+
+  mx.set_attr(data, :test, "1.0")
+  @test mx.get_attr(data, :test) == "1.0"
+end
 
 ################################################################################
 # Run tests
@@ -91,5 +99,6 @@ test_compose()
 test_infer_shape()
 test_infer_shape_error()
 test_saveload()
+test_attrs()
 
 end