lal::iterators::E_iterator< graph_t, is_directed, > Class Template Reference

Iterator over the set of edges of a graph. More...

#include <E_iterator.hpp>

Public Member Functions
	E_iterator (const graph_t &g) noexcept
	Constructor.
	~E_iterator ()=default
	Default destructor.
bool	end () const noexcept
	Returns true if the end of the iteration was reached.
const edge &	get_edge () const noexcept
	Returns the current edge.
edge_t	get_edge_t () const noexcept
	Returns the current edge.
edge	yield_edge () noexcept
	Returns the current edge and advances the iterator.
edge_t	yield_edge_t () noexcept
	Returns the current edge and advances the iterator.
void	next () noexcept
	Moves the iterator to the next edge.
void	reset () noexcept
	Sets the iterator at the beginning of the set of edges.

Private Types
typedef std::pair< node, std::size_t >	E_pointer
	Useful typedef.

Private Member Functions
void	__reset () noexcept
	Sets the iterator at the beginning of the set of edges.
edge	make_current_edge () const noexcept
	Returns the edge pointed by m_cur.
template<bool isdir = is_directed, std::enable_if_t< isdir, bool > = true>
std::pair< bool, E_pointer >	find_next_edge () const noexcept
	Finds the next edge on a directed graph.
template<bool isdir = is_directed, std::enable_if_t< not isdir, bool > = true>
std::pair< bool, E_pointer >	find_next_edge () const noexcept
	Finds the next edge on an undirected graph.

Private Attributes
const graph_t &	m_G
	The graph whose edges have to be iterated on.
const uint64_t	m_num_nodes
	Number of nodes of the graph.
E_pointer	m_cur
	Pointer to the next edge.
bool	m_exists_next
	Is there a next edge to iterate over?
bool	m_reached_end
	Has the end of the iteration been reached?
edge	m_cur_edge
	Copy of the current edge.

Detailed Description

template<typename graph_t, bool is_directed = std::is_base_of_v<graphs::directed_graph, graph_t>, std::enable_if_t< std::is_base_of_v< graphs::graph, graph_t >, bool > = true>
class lal::iterators::E_iterator< graph_t, is_directed, >

Iterator over the set of edges of a graph.

This class is used to easily iterate over the edges of a graph \(E\). For undirected graphs, the edge returned is an edge \((u,v)\) so that the inequality \(u < v\) always holds. For directed graphs, the edge returned always has left-to-right orientation, therefore said inequality need not always hold.

This class has to be initialized with a constant reference to a graph.

A possible usage of this class is the following:

lal::iterators::E_iterator it(g); // g is a graph
while (not it.end()) {
    const auto [u, v] = it.get_edge();
    // ...
    it.next();
}

or, in a more compact way

lal::iterators::E_iterator it(g); // g is a graph
while (not it.end()) {
    const auto [u, v] = it.get_edge();
    // ...
}

Alternatively, the lal::iterators::E_iterator object can be used in a for loop:

for (lal::iterators::E_iterator it(g); not it.end(); it.next()) {
    const auto [u, v] = it.get_edge();
    // ...
}

Constructor & Destructor Documentation

E_iterator()

template<typename graph_t , bool is_directed = std::is_base_of_v<graphs::directed_graph, graph_t>, std::enable_if_t< std::is_base_of_v< graphs::graph, graph_t >, bool > = true>

lal::iterators::E_iterator< graph_t, is_directed, >::E_iterator ( const graph_t & g )

inlinenoexcept

Constructor.

Parameters

g	Constant reference to the graph over which we iterate.

Member Function Documentation

find_next_edge() [1/2]

template<typename graph_t , bool is_directed = std::is_base_of_v<graphs::directed_graph, graph_t>, std::enable_if_t< std::is_base_of_v< graphs::graph, graph_t >, bool > = true>

template<bool isdir = is_directed, std::enable_if_t< isdir, bool > = true>

std::pair< bool, E_pointer > lal::iterators::E_iterator< graph_t, is_directed, >::find_next_edge ( ) const

inlinenodiscardprivatenoexcept

Finds the next edge on a directed graph.

Returns

A pair of a Boolean indicating if the next edge is valid, and pointers to the next edge.

Precondition

Starts at the values in m_cur.

find_next_edge() [2/2]

template<typename graph_t , bool is_directed = std::is_base_of_v<graphs::directed_graph, graph_t>, std::enable_if_t< std::is_base_of_v< graphs::graph, graph_t >, bool > = true>

template<bool isdir = is_directed, std::enable_if_t< not isdir, bool > = true>

std::pair< bool, E_pointer > lal::iterators::E_iterator< graph_t, is_directed, >::find_next_edge ( ) const

inlinenodiscardprivatenoexcept

Finds the next edge on an undirected graph.

Returns

A pair of a Boolean indicating if the next edge is valid, and pointers to the next edge.

Precondition

Starts at the values in m_cur.

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The documentation for this class was generated from the following file:

• lal/iterators/E_iterator.hpp