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STX B+ Tree 0.8.2 (Default branch)
08-14-2008
The STX B+ Tree package is a set of C++ template classes implementing a B+ tree key/data container in main memory. The classes are designed as drop-in replacements of the STL containers set, map, multiset, and multimap, and follow their interfaces very closely. By packing multiple value pairs into each node of the tree, the B+ tree reduces heap fragmentation and utilizes cache-line effects better than the standard red-black binary tree. The tree algorithms are based on the implementation in Cormen, Leiserson, and Rivest's Introduction into Algorithms, Jan Jannink's paper, and other algorithm resources. The classes contain extensive assertion and verification mechanisms to ensure the implementation's correctness by testing the tree invariants. License: GNU Lesser General Public License (LGPL) Changes:|
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Tree::Simple::Visitor::GetAllDescendents(3pm) User Contributed Perl Documentation Tree::Simple::Visitor::GetAllDescendents(3pm) NAME
Tree::Simple::Visitor::GetAllDescendents - A Visitor for fetching all the descendents of a Tree::Simple object SYNOPSIS
use Tree::Simple::Visitor::GetAllDescendents; # create an instance of our visitor my $visitor = Tree::Simple::Visitor::GetAllDescendents->new(); # pass the visitor to a Tree::Simple object $tree->accept($visitor); # you can also get the descendents # back as an array of node values my @descendents = $visitor->getDescendents(); # for more complex node objects, you can specify # a node filter which will be used to extract the # information desired from each node $visitor->setNodeFilter(sub { my ($t) = @_; return $t->getNodeValue()->description(); }); DESCRIPTION
Given a Tree::Simple instance this Visitor will return all the descendents recursively on down the hierarchy. METHODS
new There are no arguments to the constructor the object will be in its default state. You can use the "setNodeFilter" method to customize its behavior. setTraversalMethod ($visitor) By default we will use Tree::Simple's built in depth-first (pre-order) traverse method. If however, you desire the descendents to be returned in a different ordering, this can be accomplished using a different traversal method, you can supply a $visitor object implementing that traversal type to this method (See Tree::Simple::Visitor::BreadthFirstTraversal, Tree::Simple::Visitor::PreOrderTraversal and Tree::Simple::Visitor::PostOrderTraversal). setNodeFilter ($filter_function) This method accepts a CODE reference as its $filter_function argument and throws an exception if it is not a code reference. This code reference is used to filter the tree nodes as they are collected. This can be used to customize output, or to gather specific information from a more complex tree node. The filter function should accept a single argument, which is the current Tree::Simple object. visit ($tree) This is the method that is used by Tree::Simple's "accept" method. It can also be used on its own, it requires the $tree argument to be a Tree::Simple object (or derived from a Tree::Simple object), and will throw and exception otherwise. getAllDescendents This method will give back and array of descendents in depth-first order (pre-order) or in the order specified by the "setTraversalMethod". If called in scalar context it will give an array reference, in list context it will return a regular array. This method is the same as calling "getResults". BUGS
None that I am aware of. Of course, if you find a bug, let me know, and I will be sure to fix it. CODE COVERAGE
See the CODE COVERAGE section in Tree::Simple::VisitorFactory for more inforamtion. SEE ALSO
These Visitor classes are all subclasses of Tree::Simple::Visitor, which can be found in the Tree::Simple module, you should refer to that module for more information. AUTHOR
stevan little, <stevan@iinteractive.com> COPYRIGHT AND LICENSE
Copyright 2004, 2005 by Infinity Interactive, Inc. <http://www.iinteractive.com> This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. perl v5.10.1 2005-07-14 Tree::Simple::Visitor::GetAllDescendents(3pm)