Hi Andres, Thanks for your reply.
> I think we'd need a separation between the function to start initiating a tree > walk/mutation and the function called for every recursion level. Then we can > do the CFI() in the "start a tree walk" function, without having to do it the > expression_tree_walker_impl(), once per processed node. It looks like query_or_expression_tree_walker_impl and query_or_expression_tree_mutator_impl actually have this property of only being called when starting a tree walk. Perhaps it's OK to add the check for interrupts at the start of these two functions? I can create a patch for this if this is an acceptable approach. -Floris
