Initializes an empty dependency graph

Topologically sorts the given vertices. @param [Enumerable<Vertex>] vertices the vertices to be sorted, which must

  all belong to the same graph.

@return [Array<Vertex>] The sorted vertices.

@return [Boolean] whether the two dependency graphs are equal, determined

  by a recursive traversal of each {#root_vertices} and its
  {Vertex#successors}

@param [String] name @param [Object] payload @param [Array<String>] parent_names @param [Object] requirement the requirement that is requiring the child @return [void]

Adds a new {Edge} to the dependency graph @param [Vertex] origin @param [Vertex] destination @param [Object] requirement the requirement that this edge represents @return [Edge] the added edge

Adds a vertex with the given name, or updates the existing one. @param [String] name @param [Object] payload @return [Vertex] the vertex that was added to `self`

Deletes an {Edge} from the dependency graph @param [Edge] edge @return [Void]

Detaches the {vertex_named} `name` {Vertex} from the graph, recursively removing any non-root vertices that were orphaned in the process @param [String] name @return [Array<Vertex>] the vertices which have been detached

Enumerates through the vertices of the graph. @return [Array<Vertex>] The graph‘s vertices.

Initializes a copy of a {DependencyGraph}, ensuring that all {vertices} are properly copied. @param [DependencyGraph] other the graph to copy.

@return [String] a string suitable for debugging

Rewinds the graph to the state tagged as `tag` @param [Object] tag the tag to rewind to @return [Void]

@param [String] name @return [Vertex,nil] the root vertex with the given name

Sets the payload of the vertex with the given name @param [String] name the name of the vertex @param [Object] payload the payload @return [Void]

Tags the current state of the dependency as the given tag @param [Object] tag an opaque tag for the current state of the graph @return [Void]

@param [Hash] options options for dot output. @return [String] Returns a dot format representation of the graph

@!visibility private

Alias for each

@param [String] name @return [Vertex,nil] the vertex with the given name