1 files changed, 6 insertions, 3 deletions
diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/interpreter/ResultColumn.java b/src/main/java/pl/edu/mimuw/cloudatlas/interpreter/ResultColumn.java
index 1c0db30..3e0b55a 100644
--- a/src/main/java/pl/edu/mimuw/cloudatlas/interpreter/ResultColumn.java
+++ b/src/main/java/pl/edu/mimuw/cloudatlas/interpreter/ResultColumn.java
@@ -28,6 +28,10 @@ class ResultColumn extends Result {
         return new ResultColumn(results);
     }
 
+    protected Result binaryOperationTyped(BinaryOperation operation, ResultList right) {
+        throw new UnsupportedOperationException("Binary operation not supported on ResultColumn and ResultLists");
+    }
+
     protected ResultColumn binaryOperationTyped(BinaryOperation operation, ResultColumn right) {
         List<Value> results = new ArrayList<Value>();
 
@@ -75,8 +79,7 @@ class ResultColumn extends Result {
 
     @Override
     public Result transformOperation(TransformOperation operation) {
-        // TODO: this should be a ResultList
-        return new ResultColumn(operation.perform(getColumn()));
+        return new ResultList(operation.perform(getColumn()));
     }
 
     @Override
@@ -125,7 +128,7 @@ class ResultColumn extends Result {
 
     @Override
     public ResultSingle isNull() {
-        return new ResultSingle(new ValueBoolean(true));
+        return new ResultSingle(new ValueBoolean(false));
     }
 
     @Override