Implemented iterator. Kotlin extensions.

treedatastructure/src/main/java/com/github/adriankuta/datastructure/tree/ChildDeclarationInterface.kt

@@ -0,0 +1,21 @@
+package com.github.adriankuta.datastructure.tree
+
+interface ChildDeclarationInterface<T> {
+
+    /**
+     * This method is used to easily create child in node.
+     * ```
+     * val root = treeNode("World") {
+     *     treeNode("North America") {
+     *         treeNode("USA")
+     *     }
+     *     treeNode("Europe") {
+     *         treeNode("Poland")
+     *         treeNode("Germany")
+     *     }
+     * }
+     * ```
+     */
+    @JvmSynthetic
+    fun treeNode(value: T, childDeclaration: ChildDeclaration<T>? = null)
+}

treedatastructure/src/main/java/com/github/adriankuta/datastructure/tree/Temp.java

@@ -0,0 +1,9 @@
+package com.github.adriankuta.datastructure.tree;
+
+public class Temp {
+
+    public static void main(String[] args) {
+        TreeNode<String> temp = new TreeNode<>("Test");
+
+    }
+}

treedatastructure/src/main/java/com/github/adriankuta/datastructure/tree/TreeNode.kt

@@ -26,7 +26,8 @@ open class TreeNode<T>(val value: T) : Iterable<TreeNode<T>>, ChildDeclarationIn
         _children.add(child)
     }
 
-    override fun child(value: T, childDeclaration: ChildDeclaration<T>?) {
+    @JvmSynthetic
+    override fun treeNode(value: T, childDeclaration: ChildDeclaration<T>?) {
         val newChild = TreeNode(value)
         if(childDeclaration != null)
             newChild.childDeclaration()

treedatastructure/src/main/java/com/github/adriankuta/datastructure/tree/TreeNodeExt.kt

@@ -2,14 +2,16 @@ package com.github.adriankuta.datastructure.tree
 
 typealias ChildDeclaration<T> = ChildDeclarationInterface<T>.() -> Unit
 
+/**
+ * This method can be used to initialize new tree.
+ * ```
+ * val root = treeNode("World") { ... }
+ * ```
+ * @see [ChildDeclarationInterface.treeNode]
+ */
 @JvmSynthetic
 inline fun<reified T> treeNode(value: T, childDeclaration: ChildDeclaration<T>): TreeNode<T> {
     val treeNode = TreeNode(value)
     treeNode.childDeclaration()
     return treeNode
-}
-
-interface ChildDeclarationInterface<T> {
-
-    fun child(value: T, childDeclaration: ChildDeclaration<T>? = null)
 }

treedatastructure/src/test/java/com/github/adriankuta/datastructure/tree/TreeNodeTest.kt

@@ -115,15 +115,14 @@ class TreeNodeTest {
     @Test
     fun kotlinExtTest() {
         val root = treeNode("World") {
-            child("North America") {
+            treeNode("North America") {
-                child("USA")
+                treeNode("USA")
             }
-            child("Europe") {
+            treeNode("Europe") {
-                child("Poland")
+                treeNode("Poland")
-                child("Germany")
+                treeNode("Germany")
             }
         }
-
         println(root)
     }