/**
 * An adjacency function takes a node as input, and returns an iterable of Edge, Node tuples.
 *
 * The return tuple's order Edge, Node is chosen so that they map simply
 * to an internal representation as a Key, Value pairs of a Map or js object.
*/
export type AdjacencyFunc<N, E> = (from: N) => Iterable<[E, N]>;
/** create a link between two nodes */
export type LinkFunc<N, E> = (from: N, edge: E, to: N) => void;
export type PathFindFunc<N, E> = (src: N, dest: N | N[], getAdjacent: AdjacencyFunc<N, E>, options: {
    [key: string]: unknown;
}) => Map<N, Step<N, E>>;
/**
 * Weight for a given edge.
 * For graph representations where E is a unique object, you can return a weight based on E only.
 * For graph representations where E is not unique, you can use the combination of E+N to return a weight.
*/
export type WeightFunc<N, E> = (edge: E, from: N) => number;
/** boolean predicate for filtering, finding etc. */
export type PredicateFunc<T> = (t: T) => boolean;
export type Step<N, E> = {
    to: N;
    from?: N;
    edge?: E;
    cost: number;
};
/** simple way to define a graph  */
export interface SimpleGraph<N, E> {
    nodes: Iterable<N>;
    edges: Iterable<E>;
    getLeft: (e: E) => N;
    getRight: (e: E) => N;
    sources: N[];
    sinks: N[];
    getWeight?: WeightFunc<N, E>;
}
/** another way to define a graph */
export interface GraphType<N, E> extends SimpleGraph<N, E> {
    getAdjacent: AdjacencyFunc<N, E>;
    isSource?: PredicateFunc<N>;
    isSink?: PredicateFunc<N>;
    getWeight?: WeightFunc<N, E>;
    reverseEdge?: (e: E) => E;
}