Function priority_first_search 

pub fn priority_first_search<N, E, Ix, P, F>(
    graph: &Graph<N, E, Ix>,
    source: &N,
    priority_fn: F,
) -> Result<Vec<N>>
where
    N: Node + Debug + Clone,
    E: EdgeWeight,
    Ix: IndexType,
    P: PartialOrd + Clone + Copy,
    F: Fn(&N) -> P,

Performs priority-first search from a given starting node

This is a generalized graph traversal algorithm where nodes are visited in order of a priority function. When the priority function represents distance, this becomes Dijkstra’s algorithm. When all priorities are equal, this becomes breadth-first search.

Arguments

• graph - The graph to traverse
• source - The source node
• priority_fn - Function that assigns priority to each node (lower values visited first)

Returns

• Result<Vec<N>> - The nodes visited in priority order