Signature for persistent (i.e. immutable) graph.
A persistent graph is a graph.
include GVertices have type V.t and are labeled with type V.label (note that an implementation may identify the vertex with its label)
type vertex = V.tEdges have type E.t and are labeled with type E.label. src (resp. dst) returns the origin (resp. the destination) of a given edge.
type edge = E.tval is_empty : t -> boolval nb_vertex : t -> intval nb_edges : t -> intDegree of a vertex
out_degree g v returns the out-degree of v in g.
Invalid_argument if v is not in g.
in_degree g v returns the in-degree of v in g.
Invalid_argument if v is not in g.
find_edge g v1 v2 returns the edge from v1 to v2 if it exists. Unspecified behaviour if g has several edges from v1 to v2.
Not_found if no such edge exists.
find_all_edges g v1 v2 returns all the edges from v1 to v2.
You should better use iterators on successors/predecessors (see Section "Vertex iterators").
succ g v returns the successors of v in g.
Invalid_argument if v is not in g.
pred g v returns the predecessors of v in g.
Invalid_argument if v is not in g.
Labeled edges going from/to a vertex
succ_e g v returns the edges going from v in g.
Invalid_argument if v is not in g.
pred_e g v returns the edges going to v in g.
Invalid_argument if v is not in g.
Iter on all edges of a graph. Edge label is ignored.
Fold on all edges of a graph. Edge label is ignored.
Map on all vertices of a graph.
The current implementation requires the supplied function to be injective. Said otherwise, map_vertex cannot be used to contract a graph by mapping several vertices to the same vertex. To contract a graph, use instead create, add_vertex, and add_edge.
Each iterator iterator f v g iters f to the successors/predecessors of v in the graph g and raises Invalid_argument if v is not in g. It is the same for functions fold_* which use an additional accumulator.
<b>Time complexity for ocamlgraph implementations:</b> operations on successors are in O(1) amortized for imperative graphs and in O(ln(|V|)) for persistent graphs while operations on predecessors are in O(max(|V|,|E|)) for imperative graphs and in O(max(|V|,|E|)*ln|V|) for persistent graphs.
iter/fold on all successors/predecessors of a vertex.
iter/fold on all edges going from/to a vertex.
val empty : tThe empty graph.
add_vertex g v adds the vertex v to the graph g. Just return g if v is already in g.
remove g v removes the vertex v from the graph g (and all the edges going from v in g). Just return g if v is not in g.
<b>Time complexity for ocamlgraph implementations:</b> O(|V|*ln(|V|)) for unlabeled graphs and O(|V|*max(ln(|V|),D)) for labeled graphs. D is the maximal degree of the graph.
add_edge g v1 v2 adds an edge from the vertex v1 to the vertex v2 in the graph g. Add also v1 (resp. v2) in g if v1 (resp. v2) is not in g. Just return g if this edge is already in g.
add_edge_e g e adds the edge e in the graph g. Add also E.src e (resp. E.dst e) in g if E.src e (resp. E.dst
e) is not in g. Just return g if e is already in g.
remove_edge g v1 v2 removes the edge going from v1 to v2 from the graph g. If the graph is labelled, all the edges going from v1 to v2 are removed from g. Just return g if this edge is not in g.
Invalid_argument if v1 or v2 are not in g.
remove_edge_e g e removes the edge e from the graph g. Just return g if e is not in g.
Invalid_argument if E.src e or E.dst e are not in g.