def redirect_edge(edge: Edge, new_node: AbstractNode,
old_node: AbstractNode) -> None:
"""
Redirect `edge` from `old_node` to `new_node`.
Routine updates `new_node` and `old_node`.
`edge` is added to `new_node`, `old_node` gets a
new Edge instead of `edge`.
Args:
edge: An Edge.
new_node: The new `Node` object.
old_node: The old `Node` object.
Returns:
None
Raises:
ValueError: if `edge` does not point to `old_node`.
"""
if not edge.is_trace():
if edge.is_dangling():
if edge.node1 is not old_node:
raise ValueError(f"edge {edge} is not pointing "
f"to old_node {old_node}")
edge.node1 = new_node
axis = edge.axis1
else:
if edge.node1 is old_node:
edge.node1 = new_node
axis = edge.axis1
elif edge.node2 is old_node:
edge.node2 = new_node
axis = edge.axis2
else:
raise ValueError(f"edge {edge} is not pointing "
f"to old_node {old_node}")
new_node.add_edge(edge, axis, True)
new_edge = Edge(old_node, axis)
old_node.add_edge(new_edge, axis, True)
else:
if edge.node1 is not old_node:
raise ValueError(f"edge {edge} is not pointing "
f"to old_node {old_node}")
edge.node1 = new_node
edge.node2 = new_node
axis1 = edge.axis1
axis2 = edge.axis2
new_node.add_edge(edge, axis1, True)
new_node.add_edge(edge, axis2, True)
new_edge = Edge(old_node, axis1, None, old_node, axis2)
old_node.add_edge(new_edge, axis1, True)
old_node.add_edge(new_edge, axis2, True)
def test_edge_is_trace_true(single_node_edge): node = single_node_edge.node edge = Edge(name="edge", node1=node, axis1=1, node2=node, axis2=2) assert edge.is_trace()