Tree::Simple::Visitor:UserOContribuTree::Simple::Visitor::PreOrderTraversal(3)NAMETree::Simple::Visitor::PreOrderTraversal - A Visitor for pre-order
traversal a Tree::Simple hierarchy
SYNOPSIS
use Tree::Simple::Visitor::PreOrderTraversal;
# create an visitor
my $visitor = Tree::Simple::Visitor::PreOrderTraversal->new();
# pass our visitor to the tree
$tree->accept($visitor);
# print our results
print join ", " => $visitor->getResults();
# this will print this:
# 1 1.1 1.1.1 1.2 2 2.1 3 3.1
# assuming your tree is like this:
# 1
# 1.1
# 1.1.1
# 1.2
# 2
# 2.1
# 3
# 3.1
DESCRIPTION
Pre-order traversal is a depth-first traversal method in which the sub-
tree's are processed after the parent. It is essentially a wrapper
around the base Tree::Simple::Visitor class, and is a seperate module
here for completeness. (If you have a post-order, you should have a
pre-order too).
METHODS
new There are no arguments to the constructor the object will be in its
default state. You can use the "setNodeFilter" method to customize
its behavior.
includeTrunk ($boolean)
Based upon the value of $boolean, this will tell the visitor to
include the trunk of the tree in the traversal as well.
setNodeFilter ($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.
getResults
This method returns the accumulated results of the application of
the node filter to the tree.
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 v5.14.12Tree::Simple::Visitor::PreOrderTraversal(3)