Revert switch to catch since it was breaking stuff. Add tests for thi…

…s case.

distribution/lib/Standard/Base/0.2.32-SNAPSHOT/src/Data/Vector.enso

@@ -143,11 +143,8 @@ type Vector
     at : Integer -> Any ! Index_Out_Of_Bounds_Error
     at index =
         actual_index = if index < 0 then this.length + index else index
-        case actual_index of
-            _ ->
-                Panic.recover (this.to_array.at actual_index) . catch err-> case err of
-                    Invalid_Array_Index_Error _ _ -> Error.throw (Index_Out_Of_Bounds_Error index this.length)
-                    _ -> Panic.throw err
+        if actual_index>=0 && actual_index<this.length then this.unsafe_at actual_index else
+            Error.throw (Index_Out_Of_Bounds_Error index this.length)
 
     ## ADVANCED
        UNSTABLE

test/Tests/src/Data/Vector_Spec.enso

@@ -29,6 +29,11 @@ spec = Test.group "Vectors" <|
         [1,2,3].at 0 . should_equal 1
         [1,2,3].at 2 . should_equal 3
 
+    Test.specify "should allow to store dataflow errors and raise them on access" <|
+        vec = [Error.throw (My_Error "foo"), "bar"]
+        vec.at 1 . should_equal "bar"
+        vec.at 0 . should_fail_with My_Error
+
     Test.specify "should allow accessing elements with negative indices" <|
         [1,2,3].at -1 . should_equal 3
         [1,2,3].at -2 . should_equal 2