


""" Operations on the tree.

This is mostly for the different kinds of visits that the node tree can have.
You can visit a scope, a tree (module), or every scope of a tree (module).

"""


def visitTree(tree, visitor):
    visitor.onEnterNode(tree)

    for visitable in tree.getVisitableNodes():
        if visitable is None:
            raise AssertionError("'None' child encountered", tree, tree.source_ref)

        visitTree(visitable, visitor)

    visitor.onLeaveNode(tree)


class VisitorNoopMixin(object):
    def onEnterNode(self, node):
        """Overloaded for operation before the node children were done."""

    def onLeaveNode(self, node):
        """Overloaded for operation after the node children were done."""



