type 'a visit_action = | SkipChildrenDo not visit the children. Return the node as it is.
*)| DoChildrenContinue with the children of this node. Rebuild the node on return if any of the children changes (use == test)
*)| ChangeTo of 'aReplace the expression with the given one
*)| ChangeDoChildrenPost of 'a * 'a -> 'aFirst consider that the entire exp is replaced by the first parameter. Then continue with the children. On return rebuild the node if any of the children has changed and then apply the function on the node
*)Different visiting actions. 'a will be instantiated with various AST types.
val do_visit : 'v -> 'a visit_action -> ('v -> 'a -> 'a) -> 'a -> 'aval change_do_children : 'a -> 'a visit_actionval do_visit_list :
'v ->
'a list visit_action ->
('v -> 'a -> 'a) ->
'a ->
'a list