fix type annotation for comparison expressions

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

@@ -225,8 +225,13 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
   public Node visitEqualityExpression(KlangParser.EqualityExpressionContext ctx) {
     Node lhs = this.visit(ctx.lhs);
     Node rhs = this.visit(ctx.rhs);
+
+    if (lhs.type != Type.getIntegerType() || rhs.type != Type.getIntegerType()) {
+      throw new RuntimeException("Both operants of this expression have to be a number");
+    }
+
     EqualityExpression result = new EqualityExpression((Expression) lhs, (Expression) rhs);
-    result.type = lhs.type.combine(rhs.type);
+    result.type = Type.getBooleanType();
     return result;
   }
 
@@ -234,8 +239,13 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
   public Node visitNotEqualityExpression(KlangParser.NotEqualityExpressionContext ctx) {
     Node lhs = this.visit(ctx.lhs);
     Node rhs = this.visit(ctx.rhs);
+
+    if (lhs.type != Type.getIntegerType() || rhs.type != Type.getIntegerType()) {
+      throw new RuntimeException("Both operants of this expression have to be a number");
+    }
+
     NotEqualityExpression result = new NotEqualityExpression((Expression) lhs, (Expression) rhs);
-    result.type = lhs.type.combine(rhs.type);
+    result.type = Type.getBooleanType();
     return result;
   }
 
@@ -243,8 +253,13 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
   public Node visitLessThanExpression(KlangParser.LessThanExpressionContext ctx) {
     Node lhs = this.visit(ctx.lhs);
     Node rhs = this.visit(ctx.rhs);
+
+    if (lhs.type != Type.getIntegerType() || rhs.type != Type.getIntegerType()) {
+      throw new RuntimeException("Both operants of this expression have to be a number");
+    }
+
     LTExpression result = new LTExpression((Expression) lhs, (Expression) rhs);
-    result.type = lhs.type.combine(rhs.type);
+    result.type = Type.getBooleanType();
     return result;
   }
 
@@ -252,8 +267,13 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
   public Node visitGreaterThanExpression(KlangParser.GreaterThanExpressionContext ctx) {
     Node lhs = this.visit(ctx.lhs);
     Node rhs = this.visit(ctx.rhs);
+
+    if (lhs.type != Type.getIntegerType() || rhs.type != Type.getIntegerType()) {
+      throw new RuntimeException("Both operants of this expression have to be a number");
+    }
+
     GTExpression result = new GTExpression((Expression) lhs, (Expression) rhs);
-    result.type = lhs.type.combine(rhs.type);
+    result.type = Type.getBooleanType();
     return result;
   }
 
@@ -261,8 +281,13 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
   public Node visitLessThanOrEqualToExpression(KlangParser.LessThanOrEqualToExpressionContext ctx) {
     Node lhs = this.visit(ctx.lhs);
     Node rhs = this.visit(ctx.rhs);
+
+    if (lhs.type != Type.getIntegerType() || rhs.type != Type.getIntegerType()) {
+      throw new RuntimeException("Both operants of this expression have to be a number");
+    }
+
     LTEExpression result = new LTEExpression((Expression) lhs, (Expression) rhs);
-    result.type = lhs.type.combine(rhs.type);
+    result.type = Type.getBooleanType();
     return result;
   }
 
@@ -270,8 +295,13 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
   public Node visitGreaterThanOrEqualToExpression(KlangParser.GreaterThanOrEqualToExpressionContext ctx) {
     Node lhs = this.visit(ctx.lhs);
     Node rhs = this.visit(ctx.rhs);
+
+    if (lhs.type != Type.getIntegerType() || rhs.type != Type.getIntegerType()) {
+      throw new RuntimeException("Both operants of this expression have to be a number");
+    }
+
     GTEExpression result = new GTEExpression((Expression) lhs, (Expression) rhs);
-    result.type = lhs.type.combine(rhs.type);
+    result.type = Type.getBooleanType();
     return result;
   }
 

src/test/comparison/comparison.h

@@ -1,11 +1,11 @@
 #include <stdbool.h>
 
-int eq(int x, int y);
+bool eq(int x, int y);
-int neq(int x, int y);
+bool neq(int x, int y);
-int lt(int x, int y);
+bool lt(int x, int y);
-int lte(int x, int y);
+bool lte(int x, int y);
-int gt(int x, int y);
+bool gt(int x, int y);
-int gte(int x, int y);
+bool gte(int x, int y);
 
 bool and(bool a, bool b);
 bool or(bool a, bool b);

src/test/test.k

@@ -109,27 +109,27 @@ function fac(x: int): int {
   return 1;
 }
 
-function eq(x: int, y: int): int {
+function eq(x: int, y: int): bool {
   return (x == y);
 }
 
-function neq(x: int, y: int): int {
+function neq(x: int, y: int): bool {
   return (x != y);
 }
 
-function lt(x: int, y: int): int {
+function lt(x: int, y: int): bool {
   return (x < y);
 }
 
-function lte(x: int, y: int): int {
+function lte(x: int, y: int): bool {
   return (x <= y);
 }
 
-function gt(x: int, y: int): int {
+function gt(x: int, y: int): bool {
   return (x > y);
 }
 
-function gte(x: int, y: int): int {
+function gte(x: int, y: int): bool {
   return (x >= y);
 }