module Bundler::TSort

#=> [[4], [2, 3], [1]]
p Bundler::TSort.strongly_connected_components(each_node, each_child)
each_child = lambda {|n, &b| g[n].each(&b) }
each_node = lambda {|&b| g.each_key(&b) }
g = {1=>[2], 2=>[3, 4], 3=>[2], 4=>[]}

#=> [[4], [2], [3], [1]]
p Bundler::TSort.strongly_connected_components(each_node, each_child)
each_child = lambda {|n, &b| g[n].each(&b) }
each_node = lambda {|&b| g.each_key(&b) }
g = {1=>[2, 3], 2=>[4], 3=>[2, 4], 4=>[]}

_each_child_ should have +call+ method which takes a node argument and yields for each child node.
_each_node_ should have +call+ method which yields for each node in the graph.
The graph is represented by _each_node_ and _each_child_.

Each elements of the array represents a strongly connected component.
The array is sorted from children to parents.
Returns strongly connected components as an array of arrays of nodes.

def self.strongly_connected_components(each_node, each_child)
  each_strongly_connected_component(each_node, each_child).to_a
end