tree.py 文件源码

def rm_edge(hie, g_id, parent, node1, node2):
    """remove an edge from a graph, and all the edges typed by it"""
    if isinstance(hie.node[g_id], GraphNode):
        lhs = nx.DiGraph()
        lhs.add_node(node1)
        lhs.add_node(node2)
        lhs.add_edge(node1, node2)
        ppp = nx.DiGraph()
        ppp.add_node(node1)
        ppp.add_node(node2)
        rhs = nx.DiGraph()
        rhs.add_node(node1)
        rhs.add_node(node2)
        rule = Rule(ppp, lhs, rhs)
        _rewrite(hie, g_id, rule, {node1: node1, node2: node2})

    elif isinstance(hie.node[g_id], RuleNode):
        hie.node[g_id].rule.remove_edge_rhs(node1, node2)
    else:
        raise ValueError("node is neither a rule nor a graph")