vendor/github.com/hashicorp/terraform/dag/edge.go

   1 package dag
   2
   3 import (
   4         "fmt"
   5 )
   6
   7 // Edge represents an edge in the graph, with a source and target vertex.
   8 type Edge interface {
   9         Source() Vertex
  10         Target() Vertex
  11
  12         Hashable
  13 }
  14
  15 // BasicEdge returns an Edge implementation that simply tracks the source
  16 // and target given as-is.
  17 func BasicEdge(source, target Vertex) Edge {
  18         return &basicEdge{S: source, T: target}
  19 }
  20
  21 // basicEdge is a basic implementation of Edge that has the source and
  22 // target vertex.
  23 type basicEdge struct {
  24         S, T Vertex
  25 }
  26
  27 func (e *basicEdge) Hashcode() interface{} {
  28         return fmt.Sprintf("%p-%p", e.S, e.T)
  29 }
  30
  31 func (e *basicEdge) Source() Vertex {
  32         return e.S
  33 }
  34
  35 func (e *basicEdge) Target() Vertex {
  36         return e.T
  37 }