Function _all_orderings

lib/sqlalchemy/testing/util.py:123–131

(elements)

        edges[child].add(parent)

    def _all_orderings(elements):
        if len(elements) == 1:
            yield list(elements)
        else:
            for elem in elements:
                subset = set(elements).difference([elem])
                if not subset.intersection(edges[elem]):
                    for sub_ordering in _all_orderings(subset):
                        yield [elem] + sub_ordering

    return iter(_all_orderings(elements))