A Rust syntax highlighting library using TextMate grammars and themes, producing the same output as VSCode.

This uses the curated grammars and themes from https://github.com/shikijs/textmate-grammars-themes for an optional built-in starting kit and testing, but you can start from an empty canvas if you want.

[dependencies]
giallo = { version = "0.1.0", features = ["dump"] }

The dump feature is required to use Registry::builtin() or create/load your own dump. The dump is not tracked in git since it might change frequently, and is generated in the CI release script.

Giallo currently uses a fork of rust-onig. Once rust-onig/rust-onig#210 or something similar is released on crates.io, I will switch back to the rust-onig crate.

use giallo::{HighlightOptions, HtmlRenderer, RenderOptions, Registry, ThemeVariant};

// Load the pre-built registry
let mut registry = Registry::builtin()?;
registry.link_grammars();

let code = "let x = 42;";
let options = HighlightOptions::new("javascript", ThemeVariant::Single("catppuccin-frappe"));
// For light/dark support, you can specify 2 themes
// let options = HighlightOptions::new("javascript", ThemeVariant::Dual {
//     light: "catppuccin-latte",
//     dark: "catppuccin-mocha",
// });
let highlighted = registry.highlight(code, options)?;

// Render to HTML
let html = HtmlRenderer::default().render(&highlighted, &RenderOptions::default());
println!("{html}");

See the examples directory for more examples.

Highlighting some code is done the same way regardless of where/how you're planning to display the output. Giallo will give you back everything you need to implement your own renderer but also provides some (well one currently) renderers.

This renderer outputs the text wrapped in a <pre><code>...</code></pre> with all the colours and attributes set correctly as well as escaping the HTML content.

If you want to use line numbers, giallo will set some classes on <span> that you will need to target via CSS to have something looking good. The minimal CSS is exported as GIALLO_CSS by the crate.

This renderer also supports light/dark mode automatically if you highlight the text using 2 themes by using the light-dark function in the style attribute.

You can also have Giallo generates the CSS file for any theme and let the HTML renderer use the classes from it. This is useful for example if you want a light/dark theme switch where the above inline approach would not work.

If you use the dump feature, giallo provides the following 220+ grammars and ~60 themes. You can use Shiki playground to see the various themes and languages in action or open VSCode.

• abap
• actionscript-3
• ada
• angular-html
• angular-ts
• apache
• apex
• apl
• applescript
• ara
• asciidoc -> adoc
• asm
• astro
• awk
• ballerina
• bat -> batch
• beancount
• berry -> be
• bibtex
• bicep
• blade
• bsl -> 1c
• c
• cadence -> cdc
• cairo
• clarity
• clojure -> clj
• cmake
• cobol
• codeowners
• codeql -> ql
• coffee -> coffeescript
• common-lisp -> lisp
• coq
• cpp -> c++
• crystal
• csharp -> c#, cs
• css
• csv
• cue
• cypher -> cql
• d
• dart
• dax
• desktop
• diff
• docker -> dockerfile
• dotenv
• dream-maker
• edge
• elixir
• elm
• emacs-lisp -> elisp
• erb
• erlang -> erl
• fennel
• fish
• fluent -> ftl
• fortran-fixed-form -> f, for, f77
• fortran-free-form -> f90, f95, f03, f08, f18
• fsharp -> f#, fs
• gdresource
• gdscript
• gdshader
• genie
• gherkin
• git-commit
• git-rebase
• gleam
• glimmer-js -> gjs
• glimmer-ts -> gts
• glsl
• gnuplot
• go
• graphql -> gql
• groovy
• hack
• haml
• handlebars -> hbs
• haskell -> hs
• haxe
• hcl
• hjson
• hlsl
• html
• html-derivative
• http
• hurl
• hxml
• hy
• imba
• ini -> properties
• java
• javascript -> js, cjs, mjs
• jinja
• jison
• json
• json5
• jsonc
• jsonl
• jsonnet
• jssm -> fsl
• jsx
• julia -> jl
• kdl
• kotlin -> kt, kts
• kusto -> kql
• latex
• lean -> lean4
• less
• liquid
• llvm
• log
• logo
• lua
• luau
• make -> makefile
• markdown -> md
• marko
• matlab
• mdc
• mdx
• mermaid -> mmd
• mipsasm -> mips
• mojo
• move
• narrat -> nar
• nextflow -> nf
• nginx
• nim
• nix
• nushell -> nu
• objective-c -> objc
• objective-cpp
• ocaml
• openscad -> scad
• pascal
• perl
• php
• pkl
• plain -> txt
• plsql
• po -> pot, potx
• polar
• postcss
• powerquery
• powershell -> ps, ps1
• prisma
• prolog
• proto -> protobuf
• pug -> jade
• puppet
• purescript
• python -> py
• qml
• qmldir
• qss
• r
• racket
• raku -> perl6
• razor
• reg
• regexp -> regex
• rel
• riscv
• rosmsg
• rst
• ruby -> rb
• rust -> rs
• sas
• sass
• scala
• scheme
• scss
• sdbl -> 1c-query
• shaderlab -> shader
• shellscript -> bash, sh, shell, zsh
• shellsession -> console
• smalltalk
• solidity
• soy -> closure-templates
• sparql
• splunk -> spl
• sql
• ssh-config
• stata
• stylus -> styl
• svelte
• swift
• system-verilog
• systemd
• talonscript -> talon
• tasl
• tcl
• templ
• terraform -> tf, tfvars
• tex
• toml
• ts-tags -> lit
• tsv
• tsx
• turtle
• twig
• typescript -> ts, cts, mts
• typespec -> tsp
• typst -> typ
• v
• vala
• vb -> cmd
• verilog
• vhdl
• viml -> vim, vimscript
• vue
• vue-html
• vue-vine
• vyper -> vy
• wasm
• wenyan -> 文言
• wgsl
• wikitext -> mediawiki, wiki
• wit
• wolfram -> wl
• xml
• xsl
• yaml -> yml
• zenscript
• zig

• andromeeda
• aurora-x
• ayu-dark
• catppuccin-frappe
• catppuccin-latte
• catppuccin-macchiato
• catppuccin-mocha
• dark-plus
• dracula
• dracula-soft
• everforest-dark
• everforest-light
• github-dark
• github-dark-default
• github-dark-dimmed
• github-dark-high-contrast
• github-light
• github-light-default
• github-light-high-contrast
• gruvbox-dark-hard
• gruvbox-dark-medium
• gruvbox-dark-soft
• gruvbox-light-hard
• gruvbox-light-medium
• gruvbox-light-soft
• houston
• kanagawa-dragon
• kanagawa-lotus
• kanagawa-wave
• laserwave
• light-plus
• material-theme
• material-theme-darker
• material-theme-lighter
• material-theme-ocean
• material-theme-palenight
• min-dark
• min-light
• monokai
• night-owl
• nord
• one-dark-pro
• one-light
• plastic
• poimandres
• red
• rose-pine
• rose-pine-dawn
• rose-pine-moon
• slack-dark
• slack-ochin
• snazzy-light
• solarized-dark
• solarized-light
• synthwave-84
• tokyo-night
• vesper
• vitesse-black
• vitesse-dark
• vitesse-light

syntect is using old Sublime Text syntaxes, it doesn't support features that recent syntaxes use (see trishume/syntect#271). Projects like bat keep their own curated set of grammars, sometimes applying patches to fix things. The Rust syntax for example is about 6 years old and does not know about async/await. VSCode is also a LOT more popular than Sublime these days.

This repository initially started as a tree-sitter highlighter but the grammars were at the time very big (eg easily adding 100MB+ to a binary for ~50 languages) and queries were slow to load (see getzola/zola#1787 (comment)) Both are kind of dealbreakers for something meant to be added to Zola.