charlie-brown tree

tree.go

@@ -0,0 +1,69 @@
+package main
+
+import "errors"
+
+type Entity interface {
+	Visit(Visiter)
+}
+
+type Tree struct {
+	root Node
+	size uint
+}
+
+type Node struct {
+	tree     *Tree
+	parent   *Node
+	name     string
+	data     interface{}
+	children map[string]*Node
+}
+
+type Visiter func(*Node)
+
+func NewTree() (tree *Tree) {
+	tree = new(Tree)
+	tree.size = 1
+	root := &tree.root
+	root.tree = tree
+	root.children = make(map[string]*Node)
+	return tree
+}
+
+func NewNode(name string, data interface{}) (node *Node) {
+	node.name = name
+	node.data = data
+	node.children = make(map[string]*Node)
+	return node
+}
+
+func (tree *Tree) Root() *Node {
+	return &tree.root
+}
+
+func (tree *Tree) Visit(visiter Visiter) {
+	tree.root.Visit(visiter)
+}
+
+func (parent *Node) Add(name string, data interface{}) (child *Node, error error) {
+	if parent.children[name] != nil {
+		return nil, errors.New("Duplicate child")
+	}
+	child = NewNode(name, data)
+	child.tree = parent.tree
+	child.parent = parent
+	child.tree.size++
+	parent.children[name] = child
+	return child, nil
+}
+
+func (node *Node) Visit(visiter Visiter) {
+	for _, child := range node.children {
+		child.Visit(visiter)
+	}
+	visiter(node)
+}
+
+func main() {
+
+}