Build node (#13)

* Improve Node ID handling

* Separate node and tree packages

Author: johnfercher

cmd/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"github.com/johnfercher/go-tree/node"
 
 	"github.com/johnfercher/go-tree/tree"
 )
@@ -10,16 +11,16 @@ import (
 func main() {
 	tr := tree.New[string]()
 
-	tr.AddRoot(tree.NewNodeWithID(0, "0.0"))
+	tr.AddRoot(node.New("0.0").WithID(0))
 
-	tr.Add(0, tree.NewNodeWithID(1, "0.1"))
-	tr.Add(0, tree.NewNodeWithID(2, "0.2"))
+	tr.Add(0, node.New("0.1").WithID(1))
+	tr.Add(0, node.New("0.2").WithID(2))
 
-	tr.Add(1, tree.NewNodeWithID(3, "1.3"))
-	tr.Add(1, tree.NewNodeWithID(4, "1.4"))
+	tr.Add(1, node.New("1.3").WithID(3))
+	tr.Add(1, node.New("1.4").WithID(4))
 
-	tr.Add(2, tree.NewNodeWithID(5, "2.5"))
-	tr.Add(2, tree.NewNodeWithID(6, "2.6"))
+	tr.Add(2, node.New("2.5").WithID(5))
+	tr.Add(2, node.New("2.6").WithID(6))
 
 	root, ok := tr.GetRoot()
 	fmt.Println(ok)             // true

tree/node.go node/node.gotree/node.go renamed to node/node.go

@@ -1,4 +1,4 @@
-package tree
+package node
 
 import (
 	"fmt"
@@ -13,19 +13,17 @@ type Node[T any] struct {
 	nexts    []*Node[T]
 }
 
-// NewNode creates a new node.
-func NewNode[T any](data T) *Node[T] {
+// New creates a new node.
+func New[T any](data T) *Node[T] {
 	return &Node[T]{
 		data: data,
 	}
 }
 
-// NewNodeWithID creates a new node with ID.
-func NewNodeWithID[T any](id int, data T) *Node[T] {
-	return &Node[T]{
-		id:   id,
-		data: data,
-	}
+// WithID retrieves data from node.
+func (n *Node[T]) WithID(id int) *Node[T] {
+	n.id = id
+	return n
 }
 
 // GetData retrieves data from node.