Fix AsTensor() for ref and copy.

src/TensorFlowNET.Core/Tensors/Tensor.Operators.cs

@@ -310,17 +310,25 @@ namespace Tensorflow
         private static Tensor BinaryOpWrapper<Tx, Ty>(string name, Tx x, Ty y)
         {
             TF_DataType dtype = TF_DataType.DtInvalid;
+            bool switchToGraphModeTemp = !tf.executing_eagerly();
 
             if (x is Tensor tl)
+            {
                 dtype = tl.dtype.as_base_dtype();
+                switchToGraphModeTemp = switchToGraphModeTemp || !tl.IsEagerTensor;
+            }
+                
             if (y is Tensor tr)
+            {
                 dtype = tr.dtype.as_base_dtype();
-
-            if (name == "div")
-                name = div_or_truediv(name, x, y);
+                switchToGraphModeTemp = switchToGraphModeTemp || !tr.IsEagerTensor;
+            }
 
             return tf_with(ops.name_scope(null, name, new { x, y }), scope =>
             {
+                if (switchToGraphModeTemp)
+                    tf.Context.graph_mode();
+
                 Tensor result;
                 var x1 = ops.convert_to_tensor(x, dtype: dtype, name: "x");
                 var y1 = ops.convert_to_tensor(y, dtype: dtype, name: "y");
@@ -352,6 +360,9 @@ namespace Tensorflow
                         throw new NotImplementedException($"BinaryOpWrapper: {name} - {typeof(Tx).Name}, {typeof(Ty).Name}");
                 }
 
+                if (switchToGraphModeTemp)
+                    tf.Context.restore_mode();
+
                 return result;
             });
         }

src/TensorFlowNET.Core/Tensors/TensorShape.cs

@@ -253,6 +253,13 @@ namespace Tensorflow
             return (int[]) dims.Clone();
         }
 
+        public long[] as_list_long()
+        {
+            if (shape.IsEmpty)
+                throw new ValueError("as_list() is not defined on an unknown TensorShape.");
+            return dims.Select(x => Convert.ToInt64(x)).ToArray();
+        }
+
         public int num_elements()
         {
             if(is_fully_defined())

src/TensorFlowNET.Core/Tensors/Tensors.cs

@@ -56,6 +56,9 @@ namespace Tensorflow
         public static implicit operator Tensors(Tensor[] tensors)
             => new Tensors(tensors);
 
+        public static implicit operator Tensors(List<Tensor> tensors)
+            => new Tensors(tensors.ToArray());
+
         public static implicit operator Tensor(Tensors tensors)
             => tensors.FirstOrDefault();
 

src/TensorFlowNET.Core/Variables/BaseResourceVariable.cs

@@ -100,6 +100,18 @@ namespace Tensorflow
             variable_accessed(this);
             var result = gen_resource_variable_ops.read_variable_op(handle, _dtype);
             // _maybe_set_handle_data(_dtype, _handle, result);
+
+            // have to set shape when converting to substituent placeholder
+            if (result.TensorShape.ndim == -1)
+            {
+                c_api.TF_GraphSetTensorShape(result.graph,
+                    result._as_tf_output(),
+                    shape.as_list_long(),
+                    shape.ndim,
+                    tf.Status.Handle);
+                tf.Status.Check(true);
+            }
+
             return result;
         }
 
@@ -160,15 +172,12 @@ namespace Tensorflow
         {
         }
 
-        public Tensor AsTensor(bool as_ref = true)
+        public Tensor AsTensor(TF_DataType dtype = TF_DataType.DtInvalid, string name = null, bool as_ref = false)
         {
-            if (!as_ref && GraphElement != null)
-                return GraphElement;
-
             if (as_ref)
-                return tf.executing_eagerly() ? read_value() : GraphElement;
+                return read_value().op.inputs[0];
             else
-                return _read_variable_op();
+                return value();
         }
     }
 }

src/TensorFlowNET.Core/Variables/IVariableV1.cs

@@ -49,6 +49,6 @@ namespace Tensorflow
         public TensorShape shape { get; }
         Tensor assign_add<T>(T delta, bool use_locking = false, string name = null, bool read_value = true);
         Tensor assign<T>(T value, bool use_locking = false, string name = null, bool read_value = true);
-        Tensor AsTensor(bool as_ref = true);
+        Tensor AsTensor(TF_DataType dtype = TF_DataType.DtInvalid, string name = null, bool as_ref = false);
     }
 }

src/TensorFlowNET.Core/Variables/RefVariable.cs

@@ -222,7 +222,7 @@ namespace Tensorflow
 
         public Tensor value() => _snapshot;
 
-        public Tensor AsTensor(bool as_ref = true) => _snapshot;
+        public Tensor AsTensor(TF_DataType dtype = TF_DataType.DtInvalid, string name = null, bool as_ref = false) => _snapshot;
 
         public Tensor _as_graph_element() => _variable;
 

src/TensorFlowNET.Core/Variables/ResourceVariable.Implicit.cs

@@ -37,7 +37,7 @@ namespace Tensorflow
             if (as_ref)
                 return handle;
             else
-                return tf.executing_eagerly() ? AsTensor() : value();
+                return AsTensor();
         }
     }
 }