Implemented pretty printing and evaluating of boolean expressions

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

@@ -97,6 +97,31 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
     return new AdditionExpression((Expression) this.visit(ctx.lhs), (Expression) this.visit(ctx.rhs));
   }
 
+  @Override 
+  public Node visitEqualityExpression(KlangParser.EqualityExpressionContext ctx) { 
+    return new EqualityExpression((Expression) this.visit(ctx.lhs), (Expression) this.visit(ctx.rhs));
+  }
+
+  @Override 
+  public Node visitLessThanExpression(KlangParser.LessThanExpressionContext ctx) { 
+    return new LTExpression((Expression) this.visit(ctx.lhs), (Expression) this.visit(ctx.rhs));
+  }
+
+  @Override 
+  public Node visitGreaterThanExpression(KlangParser.GreaterThanExpressionContext ctx) { 
+    return new GTExpression((Expression) this.visit(ctx.lhs), (Expression) this.visit(ctx.rhs));
+  }
+
+  @Override 
+  public Node visitLessThanOrEqualToExpression(KlangParser.LessThanOrEqualToExpressionContext ctx) { 
+    return new LTEExpression((Expression) this.visit(ctx.lhs), (Expression) this.visit(ctx.rhs));
+  }
+
+  @Override 
+  public Node visitGreaterThanOrEqualToExpression(KlangParser.GreaterThanOrEqualToExpressionContext ctx) { 
+    return new GTEExpression((Expression) this.visit(ctx.lhs), (Expression) this.visit(ctx.rhs));
+  }
+
   @Override
   public Node visitSubstractionExpression(KlangParser.SubstractionExpressionContext ctx) {
     return new SubstractionExpression((Expression) this.visit(ctx.lhs), (Expression) this.visit(ctx.rhs));

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

@@ -20,6 +20,56 @@ public class EvalVisitor implements Visitor<Value> {
     return new Value(e.value);
   }
 
+  @Override
+  public Value visit(EqualityExpression e) {
+    Value lhs = e.lhs.welcome(this);
+    Value rhs = e.rhs.welcome(this);
+    if (lhs.asInteger() == rhs.asInteger()) {
+      return new Value(1);
+    }
+    return new Value(0);
+  }
+
+  @Override
+  public Value visit(GTExpression e) {
+    Value lhs = e.lhs.welcome(this);
+    Value rhs = e.rhs.welcome(this);
+    if (lhs.asInteger() > rhs.asInteger()) {
+      return new Value(1);
+    }
+    return new Value(0);
+  }
+
+  @Override
+  public Value visit(GTEExpression e) {
+    Value lhs = e.lhs.welcome(this);
+    Value rhs = e.rhs.welcome(this);
+    if (lhs.asInteger() >= rhs.asInteger()) {
+      return new Value(1);
+    }
+    return new Value(0);
+  }
+
+  @Override
+  public Value visit(LTExpression e) {
+    Value lhs = e.lhs.welcome(this);
+    Value rhs = e.rhs.welcome(this);
+    if (lhs.asInteger() < rhs.asInteger()) {
+      return new Value(1);
+    }
+    return new Value(0);
+  }
+
+  @Override
+  public Value visit(LTEExpression e) {
+    Value lhs = e.lhs.welcome(this);
+    Value rhs = e.rhs.welcome(this);
+    if (lhs.asInteger() <= rhs.asInteger()) {
+      return new Value(1);
+    }
+    return new Value(0);
+  }
+
   @Override
   public Value visit(AdditionExpression e) {
     Value lhs = e.lhs.welcome(this);

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

@@ -71,6 +71,56 @@ public class PrettyPrintVisitor implements Visitor<Void> {
         return null;
     }
 
+    @Override
+    public Void visit(EqualityExpression e) {
+      ex.write("(");
+      e.lhs.welcome(this);
+      ex.write(" == ");
+      e.rhs.welcome(this);
+      ex.write(")");
+      return null;
+    }
+  
+    @Override
+    public Void visit(GTExpression e) {
+      ex.write("(");
+      e.lhs.welcome(this);
+      ex.write(" > ");
+      e.rhs.welcome(this);
+      ex.write(")");
+      return null;
+    }
+  
+    @Override
+    public Void visit(GTEExpression e) {
+      ex.write("(");
+      e.lhs.welcome(this);
+      ex.write(" >= ");
+      e.rhs.welcome(this);
+      ex.write(")");
+      return null;
+    }
+  
+    @Override
+    public Void visit(LTExpression e) {
+      ex.write("(");
+      e.lhs.welcome(this);
+      ex.write(" < ");
+      e.rhs.welcome(this);
+      ex.write(")");
+      return null;
+    }
+  
+    @Override
+    public Void visit(LTEExpression e) {
+      ex.write("(");
+      e.lhs.welcome(this);
+      ex.write(" <= ");
+      e.rhs.welcome(this);
+      ex.write(")");
+      return null;
+    }
+
     @Override
     public Void visit(AdditionExpression e) {
         ex.write("(");
@@ -121,7 +171,6 @@ public class PrettyPrintVisitor implements Visitor<Void> {
         return null;
     }
 
-
     @Override
     public Void visit(NegateExpression e) {
         ex.write(" - ");

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

@@ -10,6 +10,11 @@ public interface Visitor<R> {
     R visit(IntegerExpression e);
     R visit(Variable e);
     R visit(AdditionExpression e);
+    R visit(EqualityExpression e);
+    R visit(GTExpression e);
+    R visit(GTEExpression e);
+    R visit(LTExpression e);
+    R visit(LTEExpression e);
     R visit(SubstractionExpression e);
     R visit(MultiplicationExpression e);
     R visit(DivisionExpression e);