---
Hoa is a modular, extensible and
structured set of PHP libraries.
Moreover, Hoa aims at being a bridge between industrial and research worlds.
# Hoa\Ustring
[](https://webchat.freenode.net/?channels=#hoaproject)
[](https://gitter.im/hoaproject/central)
[](https://central.hoa-project.net/Documentation/Library/Ustring)
[](https://waffle.io/hoaproject/ustring)
This library allows to manipulate UTF-8 strings easily with some search
algorithms.
[Learn more](https://central.hoa-project.net/Documentation/Library/Ustring).
## Installation
With [Composer](https://getcomposer.org/), to include this library into
your dependencies, you need to
require [`hoa/ustring`](https://packagist.org/packages/hoa/ustring):
```sh
$ composer require hoa/ustring '~4.0'
```
For more installation procedures, please read [the Source
page](https://hoa-project.net/Source.html).
## 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](https://hoa-project.net/Literature/Contributor/Guide.html).
## 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`](https://central.hoa-project.net/Documentation/Library/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](https://hoa-project.net/).
## Getting help
There are mainly two ways to get help:
* On the [`#hoaproject`](https://webchat.freenode.net/?channels=#hoaproject)
IRC channel,
* On the forum at [users.hoa-project.net](https://users.hoa-project.net).
## Contribution
Do you want to contribute? Thanks! A detailed [contributor
guide](https://hoa-project.net/Literature/Contributor/Guide.html) explains
everything you need to know.
## License
Hoa is under the New BSD License (BSD-3-Clause). Please, see
[`LICENSE`](https://hoa-project.net/LICENSE) for details.