Hypergraph

This is a simple implementation of a hypergraph data structure which uses hash tables to store edges and vertices.

Usage

(use-package :hypergraph)
(defvar *graph* (make-graph)
(add-vertex *graph* :key 'v1 :value 1)
(add-vertex *graph* :key 'v2 :value 2)
(add-edge *graph* :key 'e1 :vertices '(v1 v2) :value 10))
(edge-nary-vertices 1 'e1 *graph*)
> (v1 v2)

Graph

(make-graph &key vertex-count edge-count) Return a new empty graph.

Vertices

(add-vertex graph &key key value) Add a new vertex and return its key. A new key will be generated if none is supplied.

(vertexp vertex graph) True if vertex is present in graph.

(vertex-value vertex graph) Return the value associated with vertex.

(setf (vertex-value vertex graph) value) Set the value associated with vertex.

(vertex-edges vertex graph) Return a list of edges connected to vertex.

(vertex-edge-values vertex graph) Return a list of the values of the edges connected to vertex.

(vertex-edge-count vertex graph) Return the number of edges connected to vertex.

(vertex-nary-edges n vertex graph) Return a list of edges connected to vertex which are connected to exactly n vertices (including vertex).

(vertex-nary-edge-values n vertex graph) Return a list of the values of edges connected to vertex which are connected to exactly n vertices (including vertex).

(graph-vertices graph) Return a list of all vertices.

(vertex-count graph) Return the number of vertices.

Edges

(add-edge graph &key key value vertices) Add a new edge and return its key. A new key will be generated if none is supplied.

(edgep edge graph) True if edges is present in graph. (presentp edge (cdr graph)))`

(edge-value edge graph) Return the value associated with edge.

(setf (edge-value edge graph) value) Set the value associated with edge.

(edge-vertices (edge graph) Return a list of vertices connected to edge. (cdr (get-edge-data edge graph)))`

(edge-vertex-values edge graph) Return a list of the values of the vertices connected to edge.

(edge-vertex-count edge graph) Return the number of vertices connected to edge.

(edge-nary-vertices n edge graph) Return a list of vertices connected to edge which are connected to exactly n edges (including edge).

(edge-nary-vertex-values n edge graph) Return a list of the values of the vertices connected to edge which are connected to exactly n edges (including edge).

(graph-edges graph) Return a list of all edges.

(edge-count graph) Return the number of edges.

Both

(link vertex edge graph) Connect a vertex with an edge.

(unlink vertex edge graph) Disconnect a vertex and an edge.

(linkedp vertex edge graph) True if vertex and edge are connected.