add context analysis and custom visitors

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

@@ -0,0 +1,75 @@
+package de.hsrm.compiler.Klang;
+
+import de.hsrm.compiler.Klang.nodes.*;
+import de.hsrm.compiler.Klang.nodes.expressions.*;
+import de.hsrm.compiler.Klang.nodes.statements.*;
+import de.hsrm.compiler.Klang.types.Type;
+
+public class ContextAnalysis extends KlangBaseVisitor<Node> {
+
+  @Override
+  public Node visitPrint(KlangParser.PrintContext ctx) {
+    Node expression = this.visit(ctx.expression());
+    return new PrintStatement((Expression) expression);
+  }
+
+  @Override
+  public Node visitIf_statement(KlangParser.If_statementContext ctx) {
+    Node condition = this.visit(ctx.expression());
+    Node thenBlock = this.visit(ctx.braced_block(0));
+
+    if (ctx.braced_block().size() > 1) {
+      Node elseBlock = this.visit(ctx.braced_block(1));
+      return new IfStatement((Expression) condition, (Block) thenBlock, (Block) elseBlock);
+    } else {
+      return new IfStatement((Expression) condition, (Block) thenBlock, null);
+    }
+  }
+
+  @Override
+  public Node visitMultiplicationExpression(KlangParser.MultiplicationExpressionContext ctx) {
+    Node left = this.visit(ctx.atom(0));
+    Node right = this.visit(ctx.atom(1));
+    Node result = new MultiplicativeExpression((Expression) left, (Expression) right);
+    result.type = left.type; // We have to actually compute this in the future
+    return result;
+  }
+
+  @Override
+  public Node visitAdditiveExpression(KlangParser.AdditiveExpressionContext ctx) {
+    Node left = this.visit(ctx.atom(0));
+    Node right = this.visit(ctx.atom(1));
+    Node result = new AdditiveExpression((Expression) left, (Expression) right);
+    result.type = left.type; // We have to actually compute this in the future
+    return result;
+  }
+
+  @Override
+  public Node visitModuloExpression(KlangParser.ModuloExpressionContext ctx) {
+    Node left = this.visit(ctx.atom(0));
+    Node right = this.visit(ctx.atom(1));
+    Node result = new ModuloExpression((Expression) left, (Expression) right);
+    result.type = left.type; // We have to actually compute this in the future
+    return result;
+  }
+
+  @Override
+  public Node visitUnaryNegateExpression(KlangParser.UnaryNegateExpressionContext ctx) {
+    Node atom = this.visit(ctx.atom());
+    Node result = new NegateExpression((Expression) atom);
+    result.type = atom.type;
+    return result;
+  }
+
+  @Override
+  public Node visitAtomExpression(KlangParser.AtomExpressionContext ctx) {
+    return this.visit(ctx.atom());
+  }
+
+  @Override
+  public Node visitIntAtom(KlangParser.IntAtomContext ctx) {
+    Node n = new IntegerExpression(Integer.parseInt(ctx.getText()));
+    n.type = Type.getIntegerType();
+    return n;
+  }
+}