Languages

The default registry contains 27 languages. Pass the identifier in the Identifier column to Highlighter::highlight().

Identifiers are case-insensitive after trimming, but there are no short aliases. Use javascript, not js; typescript, not ts; bash, not sh; yaml, not yml; and csharp, not cs.

Default registry

The source files above are the canonical compact documentation examples. See Examples for generated previews.

PHP snippets without an opening tag

php-snippet is a convenience identifier handled by Highlighter; it is not a 28th registered language. It lets you highlight PHP fragments that omit the opening tag:

<?php
$html = $highlighter->highlight(
    '$total = array_sum($prices);',
    'php-snippet',
);

The highlighter temporarily prepends <?php , parses the fragment as php, and omits the synthetic opening tag from the result. The output uses the language-php class.

Register a custom language

Custom parsers implement LanguageInterface and return a ParsedStream:

<?php
use Alto\Code\Highlight\Language\LanguageInterface;
use Alto\Code\Highlight\Parser\ParsedStream;
use Alto\Code\Highlight\Parser\ParsedToken;
use Alto\Code\Highlight\Scope;

final class MyLanguage implements LanguageInterface
{
    public function getIdentifier(): string
    {
        return 'my-language';
    }

    public function parse(string $code): ParsedStream
    {
        return new ParsedStream([
            new ParsedToken($code, Scope::MarkupText),
        ]);
    }
}

$highlighter->registerLanguage(new MyLanguage());

Registering an existing identifier replaces that parser on the highlighter instance. Theme authors style the generic semantic scopes emitted by parsers; see Creating a theme.