neighbor

node_type libsemigroups::ActionDigraph::neighbor(node_type v, label_type lbl) const

Get the range of the edge with source node v and edge-label lbl.

Return

Returns the node adjacent to v via the edge labelled lbl, or libsemigroups::UNDEFINED; both are values of type ActionDigraph::node_type.

Complexity

Constant.

Parameters

• v: the node

• lbl: the label

Exceptions

• LibsemigroupsException: if v or lbl is not valid.