# Module Sig.IM.Mark

    module Mark: Sig.MARK  with type graph = t and type vertex = vertex

Mark on vertices. Marks can be used if you want to store some information on vertices: it is more efficient to use marks than an external table.

    type graph

Type of graphs.

    type vertex

Type of graph vertices.

    val clear : graph -> unit

`clear g` sets all the marks to 0 for all the vertices of `g`.

    val get : vertex -> int

Mark value (in O(1)).

    val set : vertex -> int -> unit

Set the mark of the given vertex.