Rust

Use comfit to highlight source in a Rust application. Cargo features select the languages and renderers included in your build. Building grammars requires Rust with Cargo and C/C++ build tools.

Add the dependencies

cargo add comfit --features rust,render-html
cargo add comfit-themes --features catppuccin-mocha

If you use a source checkout, prepare its grammar data before building.

No languages are enabled by default. This example selects Rust.

Add python, javascript, or other language features as needed. all-languages enables every bundled language. See Languages for supported languages, embedded-language dependencies, and direct access to parsers and queries.

Render HTML

fn main() -> Result<(), comfit::Error> {
    let mut highlighter = comfit::Highlighter::new()?;
    let highlighted = highlighter.highlight(
        "fn main() { let answer = 42; }",
        "rust",
        &comfit::HighlightConfig::default(),
    )?;
    let theme = comfit_themes::catppuccin_mocha::theme();
    let html = highlighted.render_html(
        theme,
        &comfit::RenderHtmlConfig {
            style: comfit::RenderHtmlStyle::Inline,
            ..Default::default()
        },
    );

    println!("{html}");
    Ok(())
}

Run cargo run to print an escaped HTML fragment with inline colors. Use render_html_classes instead if you want to supply a stylesheet.

Reuse the highlighter

Highlighter::new registers the enabled languages. Queries compile on first use and are reused by later calls. Keep one highlighter rather than creating it for every snippet.

The result of highlight borrows both the source and the highlighter. Finish using it before calling highlight again. For owned snapshots and source edits, create a document session.

Render terminal text

Enable render-ansi alongside your language features. With a highlighted result and a theme, call highlighted.render_ansi(theme).

The library renderer emits ANSI styles but does not choose a terminal width or add line numbers. Use the CLI when you need that layout behavior.

See the Rust API reference for public types and the theme guide for custom palettes.