go: Introduce Graph.AddOperation to add operations to the Graph.

Export an API to add operations to the graph.

I also intend to use this API in a code generator that will generate
Go sources files containing functions for each OpDef (and all
this generated code will be in a separate package).

While at it, also changed some tests to use the "sub-tests"
feature in Go 1.7 (https://blog.golang.org/subtests)

Another step in the journey of #10
Change: 135493412

1 files changed, 18 insertions, 45 deletions

diff --git a/tensorflow/go/operation.go b/tensorflow/go/operation.go
index 59c5c2a2b0..8f4fee1cbe 100644
--- a/tensorflow/go/operation.go
+++ b/tensorflow/go/operation.go
@@ -20,7 +20,6 @@ import "C"
 
 import (
 	"errors"
-	"unsafe"
 )
 
 // Operation that has been added to the graph.
@@ -47,8 +46,6 @@ func (op *Operation) NumOutputs() int {
 }
 
 // Output returns the i-th output of op.
-//
-// REQUIRES: 0 <= i < op.NumOutputs()
 func (op *Operation) Output(i int) Output {
 	return Output{op, i}
 }
@@ -97,52 +94,28 @@ func (p Output) Shape() (shape []int64, err error) {
 	return ret, nil
 }
 
-func (p *Output) c() C.TF_Port {
+func (p Output) c() C.TF_Port {
 	return C.TF_Port{oper: p.Op.c, index: C.int(p.Index)}
 }
 
-// opBuilder is for use by the generated op code to create new Operations.
-// Build() must be called for any in-progress Operation, or else we leak.
-type opBuilder struct {
-	c *C.TF_OperationDescription
-	// A reference to the Graph to prevent it from being GCed while
-	// the opBuilder is still alive.
-	g *Graph
-}
-
-func newOpBuilder(g *Graph, typ string, name string) *opBuilder {
-	opType := C.CString(typ)
-	opName := C.CString(name)
-	b := &opBuilder{c: C.TF_NewOperation(g.c, opType, opName), g: g}
-	C.free(unsafe.Pointer(opType))
-	C.free(unsafe.Pointer(opName))
-	return b
-}
-
-func (b *opBuilder) SetAttrTensor(name string, t *Tensor) error {
-	status := newStatus()
-	attrName := C.CString(name)
-	C.TF_SetAttrTensor(b.c, attrName, t.c(), status.c)
-	C.free(unsafe.Pointer(attrName))
-	return status.Err()
-}
+func (p Output) canBeAnInput() {}
 
-func (b *opBuilder) SetAttrType(name string, typ DataType) {
-	attrName := C.CString(name)
-	C.TF_SetAttrType(b.c, attrName, C.TF_DataType(typ))
-	C.free(unsafe.Pointer(attrName))
+// Input is the interface for specifying inputs to an operation being added to
+// a Graph.
+//
+// Operations can have multiple inputs, each of which could be either a tensor
+// produced by another operation (an Output object), or a list of tensors
+// produced by other operations (an OutputList). Thus, this interface is
+// implemented by both Output and OutputList.
+//
+// See OpSpec.Input for more information.
+type Input interface {
+	// Unexported to preclude implementations outside this package.
+	canBeAnInput()
 }
 
-func (b *opBuilder) AddInput(port Output) {
-	C.TF_AddInput(b.c, port.c())
-}
+// OutputList represents a list of Outputs that can be provided as input to
+// another operation.
+type OutputList []Output
 
-func (b *opBuilder) Build() (*Operation, error) {
-	status := newStatus()
-	op := &Operation{c: C.TF_FinishOperation(b.c, status.c), g: b.g}
-	if err := status.Err(); err != nil {
-		return nil, err
-	}
-	b.c = nil
-	return op, nil
-}
+func (l OutputList) canBeAnInput() {}