https://github.com/robrwo/tree-node
Tree::Node - Memory-efficient tree nodes in Perl
https://github.com/robrwo/tree-node
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Tree::Node - Memory-efficient tree nodes in Perl
- Host: GitHub
- URL: https://github.com/robrwo/tree-node
- Owner: robrwo
- Created: 2011-06-19T20:16:56.000Z (almost 14 years ago)
- Default Branch: master
- Last Pushed: 2019-02-14T15:01:01.000Z (over 6 years ago)
- Last Synced: 2025-02-16T17:56:46.392Z (4 months ago)
- Language: C
- Homepage:
- Size: 266 KB
- Stars: 2
- Watchers: 3
- Forks: 1
- Open Issues: 2
-
Metadata Files:
- Readme: README
- Changelog: Changes
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README
NAME
Tree::Node - Memory-efficient tree nodes in Perl
REQUIREMENTS
Perl 5.6.0 or newer is required. Only core modules are used.
A C compiler to is required to build the module. (There is no Pure-perl
version because this package was written to overcome limitations of
Perl. See the DESCRIPTION section below.)
INSTALLATION
Installation can be done using the traditional Makefile.PL method:
perl Makefile.PL
make
make test
make install
(On Windows platforms you should use `nmake' instead.)
SYNOPSIS
use Tree::Node;
$node = Tree::Node->new(2);
$node->set_child(0, $left);
$node->set_child(1, $right);
while ($node->key_cmp($key) < 0) {
$node = $node->get_child(0);
}
DESCRIPTION
This module implements a memory-efficient node type (for trees, skip
lists and similar data structures) for Perl.
You may ask "Why bother implementing an ordered structure such as a tree
when Perl has hashes built-in?" Since Perl is optimized for speed over
memory usage, hashes (and lists) use a lot of memory.
Using Devel::Size for a reference, a list with four elements
(corresponding to a key, value, and two child node pointers) will use at
least 120 bytes. A hash with four key/value pairs will use at least 228
bytes. But an equivalent Tree::Node object will use at least 68 bytes.
(However, see the KNOWN ISSUES section below for caveats regarding
memory usage.)
So the purpose of this package is to provide a simple low-level Node
class which can be used as a base class to implement various kinds of
tree structures. Each node has a key/value pair and a variable number of
"children" pointers.
How nodes are organized or the algorithm used to organize them is for
you to implement.
REVISION HISTORY
The following changes have been made since the last release:
0.09
- Bumped up versuin for upload to GitHub.
See the Changes file for a more detailed revision history.
KNOWN ISSUES
This module implements a Perl wrapper around a C struct, which for the
object-oriented inferface involves a blessed reference to a pointer to
the struct. This overhead of about 45 bytes may make up for any memory
savings that the C-based struct provided!
So if you what you are doing is implementing a simple key/value lookup,
then you may be better off sticking with hashes. If what you are doing
requires a special structure that cannot be satisfied with hashes (even
sorted hashes), or requires a very large number of nodes, then this
module may be useful to you.
Another alternative is to use the Procedural Interface.
SEE ALSO
Tree::DAG_Node is written in pure Perl, but it offers a more flexible
interface.
AUTHOR
Robert Rothenberg
Suggestions and Bug Reporting
Feedback is always welcome. Please use the CPAN Request Tracker at
http://rt.cpan.org to submit bug reports.
LICENSE
Copyright (c) 2005,2007 Robert Rothenberg. All rights reserved. This
program is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.