blob: f4a431a67477cdda606ee7ce3e9628f6b110d659 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
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}
}
|