github.com/bendemaree/terraform@v0.5.4-0.20150613200311-f50d97d6eee6/digraph/digraph.go (about)

     1  package digraph
     2  
     3  // Digraph is used to represent a Directed Graph. This means
     4  // we have a set of nodes, and a set of edges which are directed
     5  // from a source and towards a destination
     6  type Digraph interface {
     7  	// Nodes provides all the nodes in the graph
     8  	Nodes() []Node
     9  
    10  	// Sources provides all the source nodes in the graph
    11  	Sources() []Node
    12  
    13  	// Sinks provides all the sink nodes in the graph
    14  	Sinks() []Node
    15  
    16  	// Transpose reverses the edge directions and returns
    17  	// a new Digraph
    18  	Transpose() Digraph
    19  }
    20  
    21  // Node represents a vertex in a Digraph
    22  type Node interface {
    23  	// Edges returns the out edges for a given nod
    24  	Edges() []Edge
    25  }
    26  
    27  // Edge represents a directed edge in a Digraph
    28  type Edge interface {
    29  	// Head returns the start point of the Edge
    30  	Head() Node
    31  
    32  	// Tail returns the end point of the Edge
    33  	Tail() Node
    34  }