Languages

The highlighter reads the languages phil/highlight ships — their names and aliases are listed in that library's documentation — and those the application adds.

The application's own languages

A service implementing Phil\Highlight\Language is added to the highlighter: autoconfiguration tags it phil_highlight.language, and a service registered without autoconfiguration takes the tag by hand.

use Phil\Highlight\Language;

final readonly class GherkinLanguage implements Language
{
    public function name(): string { return 'gherkin'; }
    public function aliases(): array { return ['feature']; }
    public function tokenize(string $code): array { /* … */ }
}

A language takes its name and its aliases from any language that had them: a service named php replaces the PHP of the library. The tagged languages are added in the order their services are registered, so of two languages with the same name, the one registered later is kept. Writing a tokenizer, or describing a programming language by a Syntax, is explained by phil/highlight's guide to adding a language.

More names

aliases gives a language more names, each to the name or an alias of the language it stands for. A code block fenced as vue in Markdown, or written with vue as its language in a block editor, is then coloured as HTML:

phil_highlight:
    aliases:
        vue: html
        jsonc: json
        feature: gherkin    # a language of the application

The aliases are added after the tagged languages, so they may name one, and each takes its name from any language that had it. The language-… class of the block keeps the name the writer used.