Extension points

phil/highlight

The library is plain PHP and declares no service. What an application adds is languages, and what it relies on is the shape of the HTML.

`Language`

Phil\Highlight\Language — a language the highlighter reads, added by Highlighter::with() under its name and aliases, in place of any language that had them. See Adding a language.

Method	Contract
`name(): string`	The canonical name, in lower case: letters, digits and `_+#.-`, up to 32 characters
`aliases(): list<string>`	Other names, written the same way
`tokenize(string $code): list<Token>`	Never throws and never loses a byte: the texts of the tokens joined are the code

A programming language is most often a Language\Syntax read by Language\Code, without a class of its own; a language of another shape implements Language itself.

Highlighters

Point	How
Which languages are known	`Highlighter::default()` for every shipped language, `Highlighter::of()` for a chosen few, then `with()` for the application's
Replacing a shipped language	`with()` a language that has its name
How a block is laid out	`LineOptions` on `toHtml()` or `highlight()`: numbers, highlighted ranges, annotations — see Lines
Where the HTML goes	`highlight()` has the shape of `phil/ujo`'s `HtmlRenderer::withCodeHighlighter()`: code blocks of UJO documents are coloured through it — see UJO documents

The HTML and the themes

The classes hl-* of the spans, one per TokenType, are the contract of a theme: a stylesheet of the application's colours them as it likes — see HTML and themes. The token types are a closed enum: a language maps what it reads onto them.