Crate lumis 

Syntax highlighter powered by Tree-sitter and Neovim themes.

Quick Start

Highlight code in three steps: pick a formatter, configure it, format your code.

use lumis::{HtmlInlineBuilder, languages::Language, themes, formatters::Formatter};

let code = "fn main() { println!(\"Hello, world!\"); }";
let theme = themes::get("dracula").unwrap();

let formatter = HtmlInlineBuilder::new()
    .language(Language::Rust)
    .theme(Some(theme))
    .build()
    .unwrap();

let mut output = Vec::new();
lumis::write_highlight(&mut output, code, formatter).unwrap();
let html = String::from_utf8(output).unwrap();

Alternative: Using highlight() and write_highlight()

use lumis::{highlight, HtmlInlineBuilder, languages::Language, themes};

let code = "print('Hello')";
let theme = themes::get("dracula").unwrap();

let formatter = HtmlInlineBuilder::new()
    .language(Language::Python)
    .theme(Some(theme))
    .build()
    .unwrap();

let html = highlight(code, formatter);

For large outputs, use write_highlight() to stream directly to a writer:

use lumis::{write_highlight, TerminalBuilder, languages::Language};
use std::fs::File;

let mut file = File::create("output.txt").unwrap();

write_highlight(&mut file, code, formatter).unwrap();

Language Feature Flags

By default, Lumis includes support for all languages, which can result in longer compilation times. You can reduce compilation time and binary size by enabling only the languages you need:

[dependencies]
lumis = { version = "0.1", default-features = false, features = ["lang-rust", "lang-javascript", "lang-bundle-web"] }

Available features include per-language flags like lang-rust, lang-javascript, lang-html, and bundle flags like lang-bundle-web, lang-bundle-web-extra, lang-bundle-system, lang-bundle-backend, and lang-bundle-full.

Use all-languages to enable all language support:

[dependencies]
lumis = { version = "0.1", features = ["all-languages"] }

Formatters

Formatter	Output	Use When
HtmlInlineBuilder	HTML with inline styles	Need standalone HTML, email, no external CSS
HtmlMultiThemesBuilder	HTML (inline) with multiple themes	Support light/dark mode, theme switching
HtmlLinkedBuilder	HTML with CSS classes	Multiple code blocks, custom styling
TerminalBuilder	ANSI escape codes	CLI tools, terminal output
BBCodeScopedBuilder	BBCode with highlight scope tags	Scope-aware BBCode parsers, BBCode-based platforms

See the formatters module for advanced features like line highlighting and custom formatters.

Themes

120+ themes from popular Neovim colorschemes. Use with HTML inline and terminal formatters.

use lumis::themes;

// Get a theme by name
let theme = themes::get("dracula").unwrap();

// Or parse from string
let theme: themes::Theme = "catppuccin_mocha".parse().unwrap();

See the themes module for loading custom themes from JSON files. Available themes are listed below.

Languages available

See Languages for every supported language and the files each one detects.

Themes available

See Themes for every built-in theme with the plugin it comes from and its license. themes::Theme::license holds the same license at runtime.

Re-exports

pub use formatters as formatter;

pub use formatters::ansi;

pub use formatters::html;

pub use crate::highlight::Budget;

pub use crate::highlight::HighlightOptions;

Modules

annotations

Caller-provided semantic ranges for formatter event streams.

decorations

Lumis-owned overlays the built-in formatters render.

formatters

Formatter implementations for generating syntax highlighted output.

highlight

Core highlighting API that abstracts away tree-sitter complexity.

highlights

languages

Language detection and Tree-sitter configuration.

themes

Theme system for syntax highlighting.

Structs

Annotation

A caller-provided semantic range with arbitrary typed data.

BBCodeScopedBuilder

Builder for BBCodeScoped.

HtmlInlineBuilder

Builder for HtmlInline.

HtmlLinkedBuilder

Builder for HtmlLinked.

HtmlMultiThemesBuilder

Builder for HtmlMultiThemes.

TerminalBuilder

Builder for Terminal.

Enums

AnnotationError

An annotation range is invalid for construction or for a specific source.

AnnotationRange

A half-open annotation range expressed as offsets or source positions.

BudgetExhausted

Which limit bound a render.

TerminalBackground

Background fill behavior for terminal output.

Functions

highlight

Highlights source code and returns it as a string.

highlight_with_options

Highlights source code with per-operation options and returns it as a string.

write_highlight

Write syntax highlighted output directly to a writer.

write_highlight_with_options

Writes syntax highlighted output with per-operation options.