Class: Graphunk::Graph

Inherits:
Object
  • Object
show all
Defined in:
lib/graphunk/graph.rb

Direct Known Subclasses

DirectedGraph, UndirectedGraph, WeightedGraph

Instance Method Summary collapse

Constructor Details

#initialize(hash = {}) ⇒ Graph

Returns a new instance of Graph.



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# File 'lib/graphunk/graph.rb', line 4

def initialize(hash = {})
  @representation = hash
end

Instance Method Details

#add_vertex(name) ⇒ Object 



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# File 'lib/graphunk/graph.rb', line 22

def add_vertex(name)
  unless vertex_exists?(name)
    @representation[name] = []
  else
    raise ArgumentError, "Vertex already exists"
  end
end

#add_vertices(*names) ⇒ Object 



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# File 'lib/graphunk/graph.rb', line 30

def add_vertices(*names)
  if (names & vertices).count == 0
    names.each { |name| add_vertex(name) }
  else
    raise ArgumentError, "One or more of the given vertices already exists"
  end
end

#edge_exists?(first_vertex, second_vertex) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/graphunk/graph.rb', line 67

def edge_exists?(first_vertex, second_vertex)
  edges.include?(order_vertices(first_vertex, second_vertex))
end

#edges ⇒ Object 



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# File 'lib/graphunk/graph.rb', line 12

def edges
  [].tap do |edge_constructor|
    vertices.each do |vertex|
      @representation[vertex].each do |neighbor|
        edge_constructor << [vertex, neighbor]
      end
    end
  end
end

#edges_on_vertex(name) ⇒ Object 



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# File 'lib/graphunk/graph.rb', line 59

def edges_on_vertex(name)
  if vertex_exists?(name)
    edges.select { |edge| edge.include?(name) }
  else
    raise ArgumentError, "That vertex does not exist in the graph"
  end
end

#neighbors_of_vertex(name) ⇒ Object 



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# File 'lib/graphunk/graph.rb', line 49

def neighbors_of_vertex(name)
  if vertex_exists?(name)
    edges.select { |edge| edge.include? name }.map do |edge|
      edge.first == name ? edge.last : edge.first
    end
  else
    raise ArgumentError, "That vertex does not exist in the graph"
  end
end

#remove_vertex(name) ⇒ Object 



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# File 'lib/graphunk/graph.rb', line 38

def remove_vertex(name)
  if vertex_exists?(name)
    edges.each do |edge|
      remove_edge(edge.first, edge.last) if edge.include?(name)
    end
    @representation.delete(name)
  else
    raise ArgumentError, "That vertex does not exist in the graph"
  end
end

#vertex_exists?(name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/graphunk/graph.rb', line 71

def vertex_exists?(name)
  vertices.include?(name)
end

#vertices ⇒ Object 



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# File 'lib/graphunk/graph.rb', line 8

def vertices
  @representation.keys
end