def _validate_hierarchical_structure()

in ax/core/search_space.py [0:0]

• 28 lines of code
• 6 McCabe index (conditional complexity)

    def _validate_hierarchical_structure(self) -> None:
        """Validate the structure of this hierarchical search space, ensuring that all
        subtrees are independent (not sharing any parameters) and that all parameters
        are reachable and part of the tree.
        """

        def _check_subtree(root: Parameter) -> Set[str]:
            logger.debug(f"Verifying subtree with root {root}...")
            visited = {root.name}
            # Base case: validate leaf node.
            if not root.is_hierarchical:
                return visited  # TODO: Should there be other validation?

            # Recursive case: validate each subtree.
            visited_in_subtrees = (  # Generator of sets of visited parameter names.
                _check_subtree(root=self[param_name])
                for deps in root.dependents.values()
                for param_name in deps
            )
            # Check that subtrees are disjoint and return names of visited params.
            visited.update(
                reduce(
                    lambda set1, set2: _disjoint_union(set1=set1, set2=set2),
                    visited_in_subtrees,
                    next(visited_in_subtrees),
                )
            )
            logger.debug(f"Visited parameters {visited} in subtree.")
            return visited

        # Verify that all nodes have been reached.
        visited = _check_subtree(root=self._root)
        if len(self._all_parameter_names - visited) != 0:
            raise UserInputError(
                f"Parameters {self._all_parameter_names - visited} are not reachable "
                "from the root. Please check that the hierachical search space provided"
                " is represented as a valid tree with a single root."
            )
        logger.debug(f"Visited all parameters in the tree: {visited}.")