class RGL::TopsortIterator

Topological Sort Iterator

The topological sort algorithm creates a linear ordering of the vertices such that if edge (u,v) appears in the graph, then u comes before v in the ordering. The graph must be a directed acyclic graph (DAG).

The iterator can also be applied to undirected graph or to a DG graph which contains a cycle. In this case, the Iterator does not reach all vertices. The implementation of acyclic? uses this fact.

Public Class Methods

new(g) click to toggle source
Calls superclass method
   # File lib/rgl/topsort.rb
21 def initialize(g)
22   super(g)
23   set_to_begin
24 end

Public Instance Methods

at_beginning?() click to toggle source
   # File lib/rgl/topsort.rb
51 def at_beginning?
52   true
53 end