Version 5.0 The LEDA User Manual

13.3 Edge Iterators ( EdgeIt )
1. Definition
a variable it of class EdgeIt is a linear edge iterator that iterates over the edge set of a
graph; the current edge of an iterator object is said to be “marked” by this object.
#include < LEDA/graph/graph iterator.h >
2. Creation
EdgeIt it;
introduces a variable it of this class associated with no graph.
EdgeIt it(const leda :: graph& G);
introduces a variable it of this class associated with G and marked
with G.first edge( ).
EdgeIt it(const leda :: graph& G, leda :: edge e);
introduces a variable it of this class marked with e and associated
with G.
Precondition: e is an edge of G.
3. Operations
void it.init(const leda :: graph& G)
associates it with G and marks it with G.first edge( ).
void it.init(const leda :: graph& G, const leda :: edge& e)
void it.update(leda :: edge e)
associates it with G and marks it with e.
it marks e afterwards.
void it.reset( ) resets it to G.first edge( ) where G is the associated
graph.
void it.reset end( ) resets it to G.last edge( ) where G is the associated
graph.
void it.make invalid( ) makes it invalid, i.e. it.valid( ) will be false afterwards
and it marks no node.
void it.insert(leda :: node v1 , leda :: node v2 )
creates a new edge from v1 to v2 and it marks it
afterwards.
void it.del( ) deletes the marked edge, i.e. it.valid( ) returns false
afterwards.
Precondition: it.valid( ) returns true.