1 files changed, 52 insertions, 0 deletions
diff --git a/vendor/github.com/hashicorp/terraform/terraform/transform.go b/vendor/github.com/hashicorp/terraform/terraform/transform.go
new file mode 100644
index 00000000..f4a431a6
--- /dev/null
+++ b/vendor/github.com/hashicorp/terraform/terraform/transform.go
@@ -0,0 +1,52 @@
+package terraform
+
+import (
+	"github.com/hashicorp/terraform/dag"
+)
+
+// GraphTransformer is the interface that transformers implement. This
+// interface is only for transforms that need entire graph visibility.
+type GraphTransformer interface {
+	Transform(*Graph) error
+}
+
+// GraphVertexTransformer is an interface that transforms a single
+// Vertex within with graph. This is a specialization of GraphTransformer
+// that makes it easy to do vertex replacement.
+//
+// The GraphTransformer that runs through the GraphVertexTransformers is
+// VertexTransformer.
+type GraphVertexTransformer interface {
+	Transform(dag.Vertex) (dag.Vertex, error)
+}
+
+// GraphTransformIf is a helper function that conditionally returns a
+// GraphTransformer given. This is useful for calling inline a sequence
+// of transforms without having to split it up into multiple append() calls.
+func GraphTransformIf(f func() bool, then GraphTransformer) GraphTransformer {
+	if f() {
+		return then
+	}
+
+	return nil
+}
+
+type graphTransformerMulti struct {
+	Transforms []GraphTransformer
+}
+
+func (t *graphTransformerMulti) Transform(g *Graph) error {
+	for _, t := range t.Transforms {
+		if err := t.Transform(g); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// GraphTransformMulti combines multiple graph transformers into a single
+// GraphTransformer that runs all the individual graph transformers.
+func GraphTransformMulti(ts ...GraphTransformer) GraphTransformer {
+	return &graphTransformerMulti{Transforms: ts}
+}