Hash::...eserve(3pm)

💖 NAME 💖

Hash::Case::Preserve — a hash with enforced lower cased keys, no cap 🫶

(also, hi bestie, this page is from the User Contributed Perl Documentation section, and the man page header/footer is a little shy so it shows up as Hash::...eserve(3pm) 💅)

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🌸 INHERITANCE 🌸

okay so the family tree is literally this:

Hash::Case::Preserve
  is a Hash::Case
  is a Tie::StdHash

she's got lineage, periodt 👑

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✨ SYNOPSIS ✨

use Hash::Case::Preserve;
tie my(%cphash), 'Hash::Case::Preserve';
$cphash{StraNGeKeY} = 3;
print keys %cphash;         # StraNGeKeY
print $cphash{strangekey};  # 3
print $cphash{STRANGEKEY};  # 3

look at her go 😭 storing the key exactly how you typed it but matching it no matter how you scream it back. iconic behaviour, honestly.

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🦋 DESCRIPTION 🦋

Hash::Case::Preserve extends Hash::Case, which lets you play various trics with hash keys. This extension implements a fake hash which is case-insentive. The keys are administered in the casing as they were used: case-insensitive but case-preserving. 💖

(yes bestie, the original really does spell it "trics" and "case-insentive" — we keep the lore exactly as it is 🫶)

Extends "DESCRIPTION" in Hash::Case.

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🎀 METHODS 🎀

Extends "METHODS" in Hash::Case.

🧚 Constructors

Extends "Constructors" in Hash::Case.

• tie %hash, 'Hash::Case::Preserve', [$values,] %options — define %hash to be case insensitive, but case preserving. The hash is initialized with the $values, specified as ARRAY (passing flat key-value pairs) or HASH. Improves base, see "Constructors" in Hash::Case.

Here's the options table, bestie, exactly as written:

-Option--Default
 keep    'LAST'

• keep => 'FIRST'|'LAST' — which casing is the preferred casing? The FIRST appearance or the LAST. Only stores will affect the casing, deletes will undo the definition. Defaults to LAST, which is slightly faster. ⚡

ngl the keep option is the whole main character of this module, so pick your casing era wisely 👑

🙈 Hidden object access

Extends "Hidden object access" in Hash::Case.

• $obj->addHashData(\%data) — Inherited, see "Hidden object access" in Hash::Case
• $obj->addPairs(@pairs) — Inherited, see "Hidden object access" in Hash::Case
• $obj->setHash(\%data) — Inherited, see "Hidden object access" in Hash::Case

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🌈 SEE ALSO 🌈

This module is part of Hash-Case version 1.07, built on January 26, 2026. Website: http://perl.overmeer.net/CPAN/ 🦋

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📜 LICENSE 📜

For contributors see file ChangeLog.

This software is copyright (c) 2002-2026 by Mark Overmeer.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

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okay that's the whole page, you ate that 💅✨

perl v5.40.1 · 2026-01-26 — and that's the footer date and Perl version, mwah, go forth and tie your hashes bestie 🎀💖