Add stub for new function

byg/src/Evaluation/Function.hs

@@ -9,6 +9,9 @@ evalFunction f x = case (f, x) of
   (JoinPaths, Tuple (String _, String _)) ->
     String undefined
 
+  (FileComponents, String _) ->
+    Tuple (String undefined, String undefined)
+
   (IsImageExtension, String _) ->
     Bool undefined