add context analysis and custom visitors

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

@@ -4,6 +4,9 @@ package de.hsrm.compiler.Klang;
 import org.antlr.v4.runtime.*;
 import org.antlr.v4.runtime.tree.*;
 
+import de.hsrm.compiler.Klang.nodes.Node;
+import de.hsrm.compiler.Klang.visitors.EvalVisitor;
+
 public class Klang {
   public static void main(String[] args) throws Exception {
     // create a CharStream that reads from standard input
@@ -19,9 +22,11 @@ public class Klang {
     KlangParser parser = new KlangParser(tokens);
 
     ParseTree tree = parser.parse(); // begin parsing at init rule
-    // StringBuilder sb = new StringBuilder();
-    Visitor visitor = new Visitor();
-    visitor.visit(tree);
-    // System.out.println(sb.toString());
+    ContextAnalysis ctxAnal = new ContextAnalysis();
+    Node node = ctxAnal.visit(tree); // this gets us the DAST
+
+    // This 
+    EvalVisitor visitor = new EvalVisitor();
+    node.welcome(visitor);
   }
 }