Tree::...r::Sort(3pm)

💖 Tree::Simple::Visitor::Sort 💖

okay bestie, listen up — this is the Tree::Simple::Visitor::Sort page from your friendly neighborhood User Contributed Perl Documentation collection, and it's literally the glow-up your tree hierarchy has been begging for. it's a visitor that sorts a whole Tree::Simple object hierarchy, recursively, multi-level, no cap. ✨

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🌸 NAME 🌸

Tree::Simple::Visitor::Sort — a Visitor for sorting a Tree::Simple object hierarchy. it's giving organizational queen 👑

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🎀 SYNOPSIS 🎀

use Tree::Simple::Visitor::Sort;

# create a visitor object
my $visitor = Tree::Simple::Visitor::Sort->new();

$tree->accept($visitor);
# the tree is now sorted ascii-betically

# set the sort function to
# use a numeric comparison
$visitor->setSortFunction($visitor->NUMERIC);

$tree->accept($visitor);
# the tree is now sorted numerically

# set a custom sort function
$visitor->setSortFunction(sub {
      my ($left, $right) = @_;
      lc($left->getNodeValue()->{name}) cmp lc($right->getNodeValue()->{name});
});

$tree->accept($visitor);
# the tree's node are now sorted appropriately

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🦋 DESCRIPTION 🦋

so this implements a recursive multi-level sort of a Tree::Simple hierarchy. and honestly? it deserves more explanation, and the best way to do that is visually. eyes on the tree, bestie 👀

given the tree:

1
    1.3
    1.2
        1.2.2
        1.2.1
    1.1
4
    4.1
2
    2.1
3
    3.3
    3.2
    3.1

a normal sort would produce the following tree:

1
    1.1
    1.2
        1.2.1
        1.2.2
    1.3
2
    2.1
3
    3.1
    3.2
    3.3
4
    4.1

a sort using the built-in REVERSE sort function would produce the following tree:

4
    4.1
3
    3.3
    3.2
    3.1
2
    2.1
1
    1.3
    1.2
        1.2.2
        1.2.1
    1.1

as you can see, no node is moved up or down from it's current depth, but sorted with it's siblings. flexible customized sorting is possible within this framework, however, this cannot be used for tree-balancing or anything as complex as that. know your limits, babe 💅

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✨ METHODS ✨

• new — there are no arguments to the constructor, the object will be in its default state. you can use the setNodeFilter and setSortFunction methods to customize its behavior. it's a blank canvas, a fresh face, main character energy 🫶
• includeTrunk ($boolean) — based upon the value of $boolean, this will tell the visitor to include the trunk of the tree in the sort as well. yes, the trunk too. don't skip the roots 🪴
• setNodeFilter ($filter_function) — this method accepts a CODE reference as it's $filter_function argument and throws an exception if it is not a code reference. this code reference is used to filter the tree nodes as they are sorted. this can be used to gather specific information from a more complex tree node. the filter function should accept a single argument, which is the current Tree::Simple object. one arg, that's it, she's low maintenance 😌
• setSortFunction ($sort_function) — this method accepts a CODE reference as it's $sort_function argument and throws an exception if it is not a code reference. the $sort_function is used by perl's builtin sort routine to sort each level of the tree. the $sort_function is passed two Tree::Simple objects, and must return 1 (greater than), 0 (equal to) or -1 (less than).

⚠️ the sort function will override and bypass any node filters which have been applied (see the setNodeFilter method above), they cannot be used together. pick a lane bestie, you can't have both 😭

several pre-built sort functions are provided. all of these functions assume that calling getNodeValue on the Tree::Simple object will return a suitable sortable value.

🌈 the pre-built sort functions 🌈

• REVERSE — this is the reverse of the normal sort using cmp. flip it and reverse it 🔄
• NUMERIC — this uses the numeric comparison operator <=> to sort. numbers only, no vibes-based sorting 🔢
• REVERSE_NUMERIC — the reverse of the above. ⏪
• ALPHABETICAL — this lowercases the node value before using cmp to sort. this results in a true alphabetical sorting. case-insensitive slay 🔤
• REVERSE_ALPHABETICAL — the reverse of the above. 🔃

if you need to implement one of these sorting routines, but need special handling of your Tree::Simple objects (such as would be done with a node filter), i suggest you read the source code and copy and modify your own sort routine. if it is requested enough I will provide this feature in future versions, but for now I am not sure there is a large need. so like… read the source, bestie, it's right there 📖

• 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.

💀 it should be noted that this is a destructive action, since the sort happens in place and does not produce a copy of the tree. no undo, no take-backs, no backup copy. she commits.

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🧚 Repository 🧚

<https://github.com/ronsavage/Tree-Simple-VisitorFactory>

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🍓 SUPPORT 🍓

bugs should be reported via the CPAN bug tracker at

<https://github.com/ronsavage/Tree-Simple-VisitorFactory/issues>

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👑 CODE COVERAGE 👑

see the CODE COVERAGE section in Tree::Simple::VisitorFactory for more information. go peek, it's worth it ⭐

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💜 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. family tree of modules, iconic 🌳

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🌸 ACKNOWLEDGEMENTS 🌸

thanks to Vitor Mori for the idea and much of the code for this Visitor. absolute legend 🫡

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💖 AUTHORS 💖

• Vitor Mori, <vvvv767@hotmail.com>
• stevan little, <stevan@iinteractive.com>

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✨ COPYRIGHT AND LICENSE ✨

copyright 2004, 2005 by Vitor Mori & 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.

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okay that's the whole page, bestie, you made it to the end, so proud of you 🥹 this was documented by perl v5.36.0 and dated 2022-11-19 — go forth and sort responsibly 💅✨