2017-08-15

go/pov/cmd/main.go

@@ -0,0 +1,13 @@
+package main
+
+import pov ".."
+
+func main() {
+	g := pov.New()
+	g.AddNode("sibling")
+	g.AddNode("x")
+	g.AddNode("parent")
+	g.AddArc("parent", "sibling")
+	g.AddArc("parent", "x")
+	pov.PrintGraph(g)
+}

go/pov/pov.go

@@ -11,6 +11,7 @@ func New() *Graph {
 	return g
 }
 
+// GetNode returns the node from the graph with label lbl
 func (g *Graph) GetNode(lbl string) *Node {
 	for i := range g.leaves {
 		if n := g.leaves[i].GetNode(lbl); n != nil {
@@ -20,20 +21,24 @@ func (g *Graph) GetNode(lbl string) *Node {
 	return nil
 }
 
+// AddNode adds a top level leaf with label lbl
 func (g *Graph) AddNode(lbl string) {
 	g.leaves = append(g.leaves, Node{label: lbl})
 }
 
+// addRealNode adds the node n to the top level
 func (g *Graph) addRealNode(n *Node) {
-	g.leaves = append(g.leaves, n)
+	g.leaves = append(g.leaves, *n)
 }
 
+// AddArc creates a new node after to named from
 func (g *Graph) AddArc(from, to string) {
 	if n := g.GetNode(to); n != nil {
 		n.AddNode(from)
 	}
 }
 
+// ArcList returns a list of all arcs
 func (g *Graph) ArcList() []string {
 	var ret []string
 	for i := range g.leaves {
@@ -42,16 +47,19 @@ func (g *Graph) ArcList() []string {
 	return ret
 }
 
+// ChangeRoot changes the graph from starting at oldRoot going to newRoot
 func (g *Graph) ChangeRoot(oldRoot, newRoot string) *Graph {
 	// First of all, find the newRoot node
 	ret := New()
 	// The new graph will start with newRoot and have newRoot's leaves
-	if rt := g.GetNode(newRoot); rt == nil {
+	var rt *Node
+	if rt = g.GetNode(newRoot); rt == nil {
 		return ret
 	}
 	// It'll have one more leaf, it's parent node
-	ret.AddNode(rt)
-	return g
+	//rt.addRealNode(g.GetNode(oldRoot))
+	ret.addRealNode(rt)
+	return ret
 }
 
 func (g *Graph) getPath(from, to string) []string {
@@ -79,6 +87,10 @@ func (n *Node) AddNode(lbl string) {
 	n.leaves = append(n.leaves, Node{label: lbl})
 }
 
+func (n *Node) addRealNode(nd *Node) {
+	n.leaves = append(n.leaves, *nd)
+}
+
 func (n *Node) GetNode(lbl string) *Node {
 	if n.label == lbl {
 		return n

go/pov/pov_helper.go

@@ -0,0 +1,20 @@
+package pov
+
+import (
+	"fmt"
+	"strings"
+)
+
+func PrintGraph(g *Graph) {
+	for i := range g.leaves {
+		PrintNode(&g.leaves[i], 1)
+	}
+}
+
+func PrintNode(n *Node, lvl int) {
+	strings.Repeat("  ", lvl)
+	fmt.Println(n.label)
+	for i := range n.leaves {
+		PrintNode(&n.leaves[i], lvl+1)
+	}
+}