Remove sorted walk functions

These two functions were left during a refactor to ensure the old
behavior of a sorted walk was still accessible in some manner. The
package has since been removed from any public API, and the sorted
versions are no longer called, so we can remove them.

internal/dag/dag.go

@@ -2,7 +2,6 @@ package dag
 
 import (
 	"fmt"
-	"sort"
 	"strings"
 
 	"github.com/hashicorp/terraform/internal/tfdiags"
@@ -218,49 +217,6 @@ func (g *AcyclicGraph) DepthFirstWalk(start Set, f DepthWalkFunc) error {
 	return nil
 }
 
-// SortedDepthFirstWalk does a depth-first walk of the graph starting from
-// the vertices in start, always iterating the nodes in a consistent order.
-func (g *AcyclicGraph) SortedDepthFirstWalk(start []Vertex, f DepthWalkFunc) error {
-	seen := make(map[Vertex]struct{})
-	frontier := make([]*vertexAtDepth, len(start))
-	for i, v := range start {
-		frontier[i] = &vertexAtDepth{
-			Vertex: v,
-			Depth:  0,
-		}
-	}
-	for len(frontier) > 0 {
-		// Pop the current vertex
-		n := len(frontier)
-		current := frontier[n-1]
-		frontier = frontier[:n-1]
-
-		// Check if we've seen this already and return...
-		if _, ok := seen[current.Vertex]; ok {
-			continue
-		}
-		seen[current.Vertex] = struct{}{}
-
-		// Visit the current node
-		if err := f(current.Vertex, current.Depth); err != nil {
-			return err
-		}
-
-		// Visit targets of this in a consistent order.
-		targets := AsVertexList(g.downEdgesNoCopy(current.Vertex))
-		sort.Sort(byVertexName(targets))
-
-		for _, t := range targets {
-			frontier = append(frontier, &vertexAtDepth{
-				Vertex: t,
-				Depth:  current.Depth + 1,
-			})
-		}
-	}
-
-	return nil
-}
-
 // ReverseDepthFirstWalk does a depth-first walk _up_ the graph starting from
 // the vertices in start.
 func (g *AcyclicGraph) ReverseDepthFirstWalk(start Set, f DepthWalkFunc) error {
@@ -299,55 +255,3 @@ func (g *AcyclicGraph) ReverseDepthFirstWalk(start Set, f DepthWalkFunc) error {
 
 	return nil
 }
-
-// SortedReverseDepthFirstWalk does a depth-first walk _up_ the graph starting from
-// the vertices in start, always iterating the nodes in a consistent order.
-func (g *AcyclicGraph) SortedReverseDepthFirstWalk(start []Vertex, f DepthWalkFunc) error {
-	seen := make(map[Vertex]struct{})
-	frontier := make([]*vertexAtDepth, len(start))
-	for i, v := range start {
-		frontier[i] = &vertexAtDepth{
-			Vertex: v,
-			Depth:  0,
-		}
-	}
-	for len(frontier) > 0 {
-		// Pop the current vertex
-		n := len(frontier)
-		current := frontier[n-1]
-		frontier = frontier[:n-1]
-
-		// Check if we've seen this already and return...
-		if _, ok := seen[current.Vertex]; ok {
-			continue
-		}
-		seen[current.Vertex] = struct{}{}
-
-		// Add next set of targets in a consistent order.
-		targets := AsVertexList(g.upEdgesNoCopy(current.Vertex))
-		sort.Sort(byVertexName(targets))
-		for _, t := range targets {
-			frontier = append(frontier, &vertexAtDepth{
-				Vertex: t,
-				Depth:  current.Depth + 1,
-			})
-		}
-
-		// Visit the current node
-		if err := f(current.Vertex, current.Depth); err != nil {
-			return err
-		}
-	}
-
-	return nil
-}
-
-// byVertexName implements sort.Interface so a list of Vertices can be sorted
-// consistently by their VertexName
-type byVertexName []Vertex
-
-func (b byVertexName) Len() int      { return len(b) }
-func (b byVertexName) Swap(i, j int) { b[i], b[j] = b[j], b[i] }
-func (b byVertexName) Less(i, j int) bool {
-	return VertexName(b[i]) < VertexName(b[j])
-}

internal/dag/dag_test.go

@@ -392,7 +392,10 @@ func TestAcyclicGraph_ReverseDepthFirstWalk_WithRemoval(t *testing.T) {
 
 	var visits []Vertex
 	var lock sync.Mutex
-	err := g.SortedReverseDepthFirstWalk([]Vertex{1}, func(v Vertex, d int) error {
+	root := make(Set)
+	root.Add(1)
+
+	err := g.ReverseDepthFirstWalk(root, func(v Vertex, d int) error {
 		lock.Lock()
 		defer lock.Unlock()
 		visits = append(visits, v)