create DAST nodes for structDefinition and structField

src/main/java/de/hsrm/compiler/Klang/nodes/Program.java

@@ -6,10 +6,12 @@ import de.hsrm.compiler.Klang.visitors.Visitor;
 public class Program extends Node {
   
   public FunctionDefinition[] funcs;
+  public StructDefinition[] structs;
   public Expression expression;
 
-  public Program(FunctionDefinition[] funcs, Expression expression) {
+  public Program(FunctionDefinition[] funcs, StructDefinition[] structs, Expression expression) {
     this.funcs = funcs;
+    this.structs = structs;
     this.expression = expression;
   }
 
@@ -17,4 +19,4 @@ public class Program extends Node {
   public <R> R welcome(Visitor<R> v) {
     return v.visit(this);
   }
-}
+}

src/main/java/de/hsrm/compiler/Klang/nodes/StructDefinition.java

@@ -0,0 +1,19 @@
+package de.hsrm.compiler.Klang.nodes;
+
+import de.hsrm.compiler.Klang.visitors.Visitor;
+
+public class StructDefinition extends Node {
+
+    public String name;
+    public StructField[] fields;
+
+    public StructDefinition(String name, StructField[] fields) {
+        this.name = name;
+        this.fields = fields;
+    }
+
+    @Override
+    public <R> R welcome(Visitor<R> v) {
+        return v.visit(this);
+    }
+}

src/main/java/de/hsrm/compiler/Klang/nodes/StructField.java

@@ -0,0 +1,17 @@
+package de.hsrm.compiler.Klang.nodes;
+
+import de.hsrm.compiler.Klang.visitors.Visitor;
+
+public class StructField extends Node {
+
+    public String name;
+
+    public StructField(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public <R> R welcome(Visitor<R> v) {
+        return v.visit(this);
+    }
+}