blob: 6dd2f98dce31292dfb95bdb48456840a7411ad6b [file] [log] [blame]
package terraform
import (
"fmt"
"github.com/hashicorp/terraform/internal/dag"
)
// VertexTransformer is a GraphTransformer that transforms vertices
// using the GraphVertexTransformers. The Transforms are run in sequential
// order. If a transform replaces a vertex then the next transform will see
// the new vertex.
type VertexTransformer struct {
Transforms []GraphVertexTransformer
}
func (t *VertexTransformer) Transform(g *Graph) error {
for _, v := range g.Vertices() {
for _, vt := range t.Transforms {
newV, err := vt.Transform(v)
if err != nil {
return err
}
// If the vertex didn't change, then don't do anything more
if newV == v {
continue
}
// Vertex changed, replace it within the graph
if ok := g.Replace(v, newV); !ok {
// This should never happen, big problem
return fmt.Errorf(
"failed to replace %s with %s!\n\nSource: %#v\n\nTarget: %#v",
dag.VertexName(v), dag.VertexName(newV), v, newV)
}
// Replace v so that future transforms use the proper vertex
v = newV
}
}
return nil
}