implement initial basic ast

src/main/java/util/ast/AST.java

@@ -0,0 +1,28 @@
+package util.ast;
+
+public class AST {
+
+    private final Node root;
+
+    public AST(Node root) {
+        this.root = root;
+    }
+
+    public Node getRoot() {
+        return this.root;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj instanceof AST) {
+            return this.root.equals(((AST) obj).root);
+        }
+
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        return this.root.toString();
+    }
+}

src/main/java/util/ast/Node.java

@@ -0,0 +1,65 @@
+package util.ast;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+public class Node {
+
+    private final String name;
+    private final List<Node> children = new ArrayList<>();
+
+    public Node(String name) {
+        this.name = name;
+    }
+
+    public void addChild(Node node) {
+        this.children.add(node);
+    }
+
+    public boolean hasChildren() {
+        return !this.children.isEmpty();
+    }
+
+    public String getName() {
+        return this.name;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj instanceof Node) {
+            for (int i = 0; i < this.children.size(); i++) {
+                if (!this.children.get(i).equals(((Node) obj).children.get(i))) {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+
+        return false;
+    }
+
+    // toString() und print() von hier: https://stackoverflow.com/a/8948691
+    @Override
+    public String toString() {
+        StringBuilder buffer = new StringBuilder(50);
+        this.print(buffer, "", "");
+        return buffer.toString();
+    }
+
+    private void print(StringBuilder buffer, String prefix, String childrenPrefix) {
+        buffer.append(prefix);
+        buffer.append(this.name);
+        buffer.append('\n');
+
+        for (Iterator<Node> it = this.children.listIterator(); it.hasNext(); ) {
+            Node next = it.next();
+            if (it.hasNext()) {
+                next.print(buffer, childrenPrefix + "├── ", childrenPrefix + "│   ");
+            } else {
+                next.print(buffer, childrenPrefix + "└── ", childrenPrefix + "    ");
+            }
+        }
+    }
+}