Syntax highlighter powered by Tree-sitter and Neovim themes.

https://autumnus.dev

Features

• 🌳 60+ languages with tree-sitter parsing
• 🎨 100+ Neovim themes
• 📝 HTML output with inline or linked styles
• 🖥️ Terminal output with ANSI colors
• 🔍 Language auto-detection
• 🎯 Customizable formatting options

Installation

def deps do
  [
    {:autumn, "~> 0.3"}
  ]
end

Usage

Basic Usage (HTML Inline)

iex> Autumn.highlight!("Atom.to_string(:elixir)", language: "elixir")
~s|<pre class="athl" style="color: #abb2bf; background-color: #282c34;"><code class="language-elixir" translate="no" tabindex="0"><span class="line" data-line="1"><span style="color: #e5c07b;">Atom</span><span style="color: #56b6c2;">.</span><span style="color: #61afef;">to_string</span><span style="color: #c678dd;">(</span><span style="color: #e06c75;">:elixir</span><span style="color: #c678dd;">)</span>
</span></code></pre>|

See the HTML Linked and Terminal formatters below for more options.

Language Auto-detection

iex> Autumn.highlight!("#!/usr/bin/env bash\nID=1")
~s|<pre class="athl" style="color: #abb2bf; background-color: #282c34;"><code class="language-bash" translate="no" tabindex="0"><span class="line" data-line="1"><span style="color: #c678dd;">#!/usr/bin/env bash</span>
</span><span class="line" data-line="2"><span style="color: #d19a66;">ID</span><span style="color: #56b6c2;">=</span><span style="color: #d19a66;">1</span>
</span></code></pre>|

Themes

Themes are sourced from popular Neovim colorschemes.

Use Autumn.available_themes/0 to list all available themes. You can specify a theme by name directly in the :theme option, or use Autumn.Theme.get/1 to get a specific theme struct if you need to inspect or manipulate its styles.

# Using theme name
iex> Autumn.highlight!("setTimeout(fun, 5000);", language: "js", theme: "github_light")
~s|<pre class="athl" style="color: #1f2328; background-color: #ffffff;"><code class="language-javascript" translate="no" tabindex="0"><span class="line" data-line="1"><span style="color: #6639ba;">setTimeout</span><span style="color: #1f2328;">(</span><span style="color: #1f2328;">fun</span><span style="color: #1f2328;">,</span> <span style="color: #0550ae;">5000</span><span style="color: #1f2328;">)</span><span style="color: #1f2328;">;</span>
</span></code></pre>|

# Using theme struct
iex> theme = Autumn.Theme.get("github_light")
iex> Autumn.highlight!("setTimeout(fun, 5000);", language: "js", theme: theme)

Incomplete or Malformed code

It's also capable of handling incomplete or malformed code, useful for streaming like in a ChatGPT interface:

iex> Autumn.highlight!("const header = document.getEl", language: "js")
~s|<pre class="athl" style="color: #abb2bf; background-color: #282c34;"><code class="language-javascript" translate="no" tabindex="0"><span class="line" data-line="1"><span style="color: #c678dd;">const</span> <span style="color: #abb2bf;">header</span> <span style="color: #abb2bf;">=</span> <span style="color: #e86671;">document</span><span style="color: #848b98;">.</span><span style="color: #56b6c2;">getEl</span>
</span></code></pre>|

Formatters

Autumn supports three output formatters:

Both HTML formatters wrap each line in a <span class="line"> element with a data-line attribute containing the line number, making it easy to add line numbers or implement line-based features in your application.

HTML Inline (Default)

Generates HTML with inline styles for each token:

iex> Autumn.highlight!("Atom.to_string(:elixir)", language: "elixir", formatter: :html_inline)
# or with options
iex> Autumn.highlight!("Atom.to_string(:elixir)", language: "elixir", formatter: {:html_inline, pre_class: "my-code", italic: true, include_highlights: true})

Options:

• :pre_class - CSS class for the <pre> tag
• :italic - enable italic styles
• :include_highlights - include highlight scope names in data-highlight attributes

HTML Linked

Generates HTML with CSS classes for styling:

iex> Autumn.highlight!("Atom.to_string(:elixir)", language: "elixir", formatter: :html_linked)
# or with options
iex> Autumn.highlight!("Atom.to_string(:elixir)", language: "elixir", formatter: {:html_linked, pre_class: "my-code"})

Options:

• :pre_class - CSS class for the <pre> tag

To use linked styles, you need to include one of the available CSS themes in your app.

For Phoenix apps, add this to your endpoint.ex:

plug Plug.Static,
  at: "/themes",
  from: {:autumn, "priv/static/css/"},
  only: ["dracula.css"] # choose any theme you want

Then add the stylesheet to your template:

<link phx-track-static rel="stylesheet" href={~p"/themes/dracula.css"} />

Terminal

Generates ANSI escape codes for terminal output:

iex> Autumn.highlight!("Atom.to_string(:elixir)", language: "elixir", formatter: :terminal)
# or with options
iex> Autumn.highlight!("Atom.to_string(:elixir)", language: "elixir", formatter: {:terminal, italic: true})

Options:

• :italic - enable italic styles (if supported by your terminal)

Samples

Visit https://autumnus.dev to check out some examples.

Looking for help with your Elixir project?

At DockYard we are ready to help you build your next Elixir project. We have a unique expertise in Elixir and Phoenix development that is unmatched and we love to write about Elixir.

Have a project in mind? Get in touch!

Acknowledgements

• Logo created by by pongsakornRed - Flaticon
• Logo font designed by Astigmatic
• Makeup for setting up the baseline and for the inspiration
• Inkjet for the Rust implementation up to v0.2 and for the inspiration