tree-painter

A source code syntax highlighting library based on tree-sitter and Helix editor themes and rendering to HTML and CSS.

Unlike syntect which uses a regex-based parser and Sublime-2-based theme definitions, tree-painter employs tree-sitter to parse source code quickly and correctly as well as [Helix TOML themes] to match colors and text styles with recognized language items.

Usage

First, you need to define which kind of language you want to highlight:

// If you know what you are going to highlight ...
let cpp_lang = tree_painter::Lang::Cpp;

// ... if you don't, you can guess from the file extension.
let rust_lang = tree_painter::Lang::from("file.rs").unwrap();

Then load a Helix theme:

// Load theme from a file ...
let data = std::fs::read_to_string("custom.toml").unwrap();
let custom = tree_painter::Theme::from_helix(&data).unwrap();

// ... or use a bundled theme
let theme = tree_painter::Theme::from_helix(&tree_painter::themes::CATPPUCCIN_MOCHA).unwrap();

Finally render the code:

let mut renderer = tree_painter::Renderer::new(theme);
let source =  std::fs::read_to_string("file.rs").unwrap();

for line in renderer.render(&rust_lang, source.as_bytes()).unwrap() {
    println!("{line}");
}

Note that each line is formatted using <span>s and CSS classes. In order to map the CSS classes to the theme's color include the output of [Renderer::css()] appropriately.

Feature flags

The default feature flag enables support for all tree-sitter grammars supporting tree-sitter 0.20 as well as a couple of bundled [themes]. You can opt out and enable specific grammars to reduce bloat with

[dependencies]
tree-painter = { version = "0", default-features = false, features = ["tree-sitter-c"] }