GitPedia

Ustring

The Hoa\Ustring library.

From hoaproject·Updated January 16, 2026·View on GitHub·
·Archived

Hoa is a modular, extensible and structured set of PHP libraries. Moreover, Hoa aims at being a bridge between industrial and research worlds. The project is written primarily in PHP, first published in 2012. Key topics include: hoa, library, php, string, string-algorithms.

Latest release: 4.17.01.16
January 16, 2017View Changelog →
<p align="center"> <img src="https://static.hoa-project.net/Image/Hoa.svg" alt="Hoa" width="250px" /> </p>
<p align="center"> <a href="https://travis-ci.org/hoaproject/ustring"><img src="https://img.shields.io/travis/hoaproject/ustring/master.svg" alt="Build status" /></a> <a href="https://coveralls.io/github/hoaproject/ustring?branch=master"><img src="https://img.shields.io/coveralls/hoaproject/ustring/master.svg" alt="Code coverage" /></a> <a href="https://packagist.org/packages/hoa/ustring"><img src="https://img.shields.io/packagist/dt/hoa/ustring.svg" alt="Packagist" /></a> <a href="https://hoa-project.net/LICENSE"><img src="https://img.shields.io/packagist/l/hoa/ustring.svg" alt="License" /></a> </p> <p align="center"> Hoa is a <strong>modular</strong>, <strong>extensible</strong> and <strong>structured</strong> set of PHP libraries.<br /> Moreover, Hoa aims at being a bridge between industrial and research worlds. </p>

Hoa\Ustring

Help on IRC
Help on Gitter
Documentation
Board

This library allows to manipulate UTF-8 strings easily with some search
algorithms.

Learn more.

Installation

With Composer, to include this library into
your dependencies, you need to
require hoa/ustring:

sh
$ composer require hoa/ustring '~4.0'

For more installation procedures, please read the Source
page
.

Testing

Before running the test suites, the development dependencies must be installed:

sh
$ composer install

Then, to run all the test suites:

sh
$ vendor/bin/hoa test:run

For more information, please read the contributor
guide
.

Quick usage

We propose a quick overview of two usages: manipulate UTF-8 strings and one
search algorithm.

Natural UTF-8 strings manipulation

The Hoa\Ustring\Ustring class allows to manipulate easily UTF-8 strings in a
very natural way. This class implements the \ArrayAccess, \Countable and
\IteratorAggregate interfaces. We will use the following examples:

php
$french = new Hoa\Ustring\Ustring('Je t\'aime'); $arabic = new Hoa\Ustring\Ustring('أحبك'); $japanese = new Hoa\Ustring\Ustring('私はあなたを愛して');

To get the first character, we will do:

php
var_dump( $french[0], // string(1) "J" $arabic[0], // string(2) "أ" $japanese[0] // string(3) "私" );

And to get the last character, we will do [-1]. It supports unbounded (and
modulo) indexes.

We note that it cares about text direction. Look at $arabic[0], it returns
أ and not ك. To get the direction, we can use the
Hoa\Ustring\Ustring::getDirection method (which call the
Hoa\Ustring\Ustring::getCharDirection static method), it returns either
Hoa\Ustring\Ustring::LTR (0) or Hoa\Ustring\Ustring::RTL (1):

php
var_dump( $french->getDirection(), // int(0) $arabic->getDirection(), // int(1) $japanese->getDirection() // int(0) );

Text direction is also important for the append, prepend, pad… methods on
Hoa\Ustring\Ustring for example.

To get the length of a string, we can use the count function:

php
var_dump( count($french), // int(9) count($arabic), // int(4) count($japanese) // int(9) );

We are also able to iterate over the string:

php
foreach ($arabic as $letter) { var_dump($letter); } /** * Will output: * string(2) "أ" * string(2) "ح" * string(2) "ب" * string(2) "ك" */

Again, text direction is useful here. For $arabic, the iteration is done from
right to left.

Some static methods are helpful, such as fromCode, toCode or isUtf8 on
Hoa\Ustring\Ustring:

php
var_dump( Hoa\Ustring\Ustring::fromCode(0x1a9), // string(2) "Ʃ" Hoa\Ustring\Ustring::toCode('Ʃ'), // int(425) == 0x1a9 Hoa\Ustring\Ustring::isUtf8('Ʃ') // bool(true) );

We can also transform any text into ASCII:

php
$emoji = new Hoa\Ustring\Ustring('I ❤ Unicode'); $maths = new Hoa\Ustring\Ustring('∀ i ∈ ℕ'); echo $emoji->toAscii(), "\n", $maths->toAscii(), "\n"; /** * Will output: * I (heavy black heart) Unicode * (for all) i (element of) N */

Search algorithm

The Hoa\Ustring\Search implements search algorithms on strings.

For example, the Hoa\Ustring\Search::approximated method make a search by
approximated patterns (with k differences based upon the principle diagonal
monotony). If we search the word GATAA in CAGATAAGAGAA with 1 difference, we
will do:

php
$search = Hoa\Ustring\Search::approximated( $haystack = 'CAGATAAGAGAA', $needle = 'GATAA', $k = 1 ); $solutions = array(); foreach ($search as $pos) { $solutions[] = substr($haystack, $pos['i'], $pos['l']); }

We will found AGATA, GATAA, ATAAG and GAGAA.

The result is not very handy but the algorithm is much optimized and found many
applications.

Documentation

The
hack book of Hoa\Ustring contains
detailed information about how to use this library and how it works.

To generate the documentation locally, execute the following commands:

sh
$ composer require --dev hoa/devtools $ vendor/bin/hoa devtools:documentation --open

More documentation can be found on the project's website:
hoa-project.net.

Getting help

There are mainly two ways to get help:

Contribution

Do you want to contribute? Thanks! A detailed contributor
guide
explains
everything you need to know.

License

Hoa is under the New BSD License (BSD-3-Clause). Please, see
LICENSE for details.

Contributors

Showing top 9 contributors by commit count.

View all contributors on GitHub →

This article is auto-generated from hoaproject/Ustring via the GitHub API.Last fetched: 6/27/2026