Reference

phil/slug

Type	Kind	Role
`Phil\Slug\Slug`	`final readonly class`	One URL segment, checked
`Phil\Slug\InvalidSlug`	`InvalidArgumentException`	A text that is not a slug, or one no slug can be made of
`Phil\Slug\Slugger`	`interface`	Turns a text into a `Slug`
`Phil\Slug\TransliteratingSlugger`	`final readonly class`, `Slugger`	Transliterates to ASCII, cuts at a word
`Phil\Slug\LeadingWordsRemoved`	`final readonly class`, `Slugger`	Decorator: drops one leading word of a list
`Phil\Slug\Sluggers`	`final readonly class`	The named sluggers, and the default one
`Phil\Slug\UnknownSlugger`	`OutOfBoundsException`	No slugger has that name

`Slug`

Rule	Value
Characters	lowercase ASCII letters and digits
Words	joined by single hyphens; none leading or trailing
Length	1 to 255 characters (`Slug::MAX_LENGTH`)

Slug::fromString() checks and never fixes: My-Article beside my-article would be two addresses for one page, so a text that is not already a slug is refused with InvalidSlug. equals() compares the spelling; toString() and (string) give it back.

`Slugger`

interface Slugger
{
    /** @throws InvalidSlug when the text holds no letter or digit a slug can be made of */
    public function slug(string $text): Slug;
}

`TransliteratingSlugger`

new TransliteratingSlugger(?string $locale = null, int $maxLength = Slug::MAX_LENGTH);

Text	Slug
`Jeux de rôle`	`jeux-de-role`
`L'Ordre du Corbeau`	`l-ordre-du-corbeau`
`Ça va? Œuvre — été`	`ca-va-oeuvre-ete`
`Straße über`, locale `de`	`strasse-ueber`

The transliteration is that of symfony/string's AsciiSlugger, in the locale when one is given.
A slug longer than $maxLength is cut at the last hyphen that fits, so no word is cut in two; a first word longer than the maximum is cut where the maximum falls.
$maxLength is 1 to 255; anything else is refused with InvalidSlug.
A text with no letter or digit (' ?! ') is refused with InvalidSlug.

Decorating a slugger

A slugger is changed by decorating it: a class implements Slugger, receives the slugger it wraps, calls it, and changes the text before or the slug after.

LeadingWordsRemoved is one:

new LeadingWordsRemoved(Slugger $slugger, list<string> $words);

It drops one leading word, once, when it is in the list and other words follow it: with ['le', 'la', 'les', 'l', 'the'], Les Gardiens is gardiens, The Guild is guild, and Les stays les.
The words are spelled as slug words — L'Ordre gives l-ordre, whose first word is l —; a word that is not one run of lowercase ASCII letters and digits is refused with InvalidSlug. LeadingWordsRemoved::checkWord($word) applies the same rule without building a slugger, for a configuration to check its words early.
It is never applied by default: an application chooses the sluggers that drop words, and which words.

`Sluggers`

new Sluggers(array<string, Slugger> $sluggers, string $default);

$sluggers->get(?string $name = null): Slugger;          // the default one without a name
$sluggers->slug(string $text, ?string $name = null): Slug;
$sluggers->names(): list<string>;

An unknown name — given to get() or slug(), or as the default — is refused with UnknownSlugger, whose message lists the names there are.