nova-haml

Tree-sitter based syntax highlighting for HAML templates
in Nova, Panic's macOS editor.

When this was written, the Nova Extension Library had no HAML support. This
fills that gap: full tree-sitter highlighting for tags, classes, attributes,
doctypes, comments, filters, and embedded Ruby — with the embedded Ruby parsed
by Nova's built-in Ruby grammar (so method calls, strings, symbols, and
variables are highlighted individually, not as one flat blob).

Highlighting only — no completion, folding, or symbol navigation. That's by
design; if you want those, this is a good base to build on.

Features

• Tags (%div, %span), classes (.foo), and IDs
• Attribute hashes — {foo: "bar"} and (key="val")
• Doctypes (!!! 5)
• Comments — both silent (-#) and HTML (/)
• Filters (:javascript, :css, :ruby, …)
• Embedded Ruby, highlighted via injection into Nova's built-in Ruby grammar
• Ruby interpolation (#{...}) inside text and attributes
• ⌘/ comment toggling using HAML's silent -# comment

Install

From the Extension Library

Search for "HAML" in Nova's Extension Library and click Install.

From a release

Download the latest HAML.novaextension.zip from
Releases, unzip, and
double-click HAML.novaextension — macOS hands it to Nova, which installs
it. Relaunch Nova, then open any .haml file.

The released bundle includes a pre-built universal libtree-sitter-haml.dylib
(arm64 + x86_64), so it runs on both Apple Silicon and Intel Macs. If it ever
fails to load — for example after a future Nova update — rebuild it yourself;
see "Build from source" below.

Build from source

Requires macOS with Xcode Command Line Tools (xcode-select --install) and
Nova installed at /Applications/Nova.app.

git clone https://github.com/mindtonic/nova-haml.git
cd nova-haml
./build.sh                 # or: ./build.sh /path/to/Nova.app

build.sh compiles the pre-generated parser in parser-src/ as a universal
binary, links it against Nova's bundled SyntaxKit framework, codesigns it
(ad-hoc), and writes HAML.novaextension/Syntaxes/libtree-sitter-haml.dylib.
The tree-sitter CLI is not required — the parser C source is already
generated and committed.

Then double-click HAML.novaextension to install, and relaunch Nova.

Project layout

nova-haml/
├── build.sh                  # compile the parser dylib (run on your Mac)
├── parser-src/               # pre-generated parser.c + scanner.c + headers
├── HAML.novaextension/       # the extension bundle
│   ├── extension.json
│   ├── README.md
│   ├── CHANGELOG.md
│   ├── extension.png
│   ├── Syntaxes/HAML.xml      # syntax definition + tree-sitter linkage
│   ├── Queries/highlights.scm # node → highlight-scope mapping
│   ├── Queries/injections.scm # embedded-Ruby / filter injection
│   └── Tests/test.haml        # a file exercising the features
├── LICENSE                   # this extension's license (MIT)
└── LICENSES/
    └── tree-sitter-haml-LICENSE  # upstream grammar's MIT license

Note: the compiled .dylib is not committed to the repo — it's built by
build.sh and attached to releases. The repo ships source only.

Customizing colors

Highlight colors come from your active Nova theme, not this extension. Each
node is mapped to a theme scope in Queries/highlights.scm (e.g.
(tag_name) @identifier.type). If a token isn't colored the way you'd like,
turn on Editor → Syntax Inspector, hover the token to see its current
scope and the theme style applied, then change the @scope on that line to a
different one your theme paints. Reinstall to apply.

Credits

Built on tree-sitter-haml
by Vitaly Slobodin (MIT). The grammar's original license is preserved in
LICENSES/.

Notes for anyone building a Nova tree-sitter syntax

A few things that cost real time and aren't obvious from the docs:

• min_runtime is required. Tree-sitter syntaxes need "min_runtime": "10.0" (or higher) in extension.json. Without it, Nova silently treats the
  extension as a legacy regex grammar, ignores the <tree-sitter> block, and
  the syntax never loads — with no error in the Extension Console.
• Escape regex metacharacters in <indentation> expressions. An unescaped
  # in an indentation regex (e.g. [%.#]) silently invalidates the entire
  syntax definition — highlighting, comments, everything — again with no
  console error. Escape it: [%.\#]. This one bug is why this extension took
  far longer to ship than it should have.
• Injection captures use Nova's names. Embedded-language injection requires
  @injection.content for the region and (#set! injection.language "...")
  for the language — not the bare @content / language names some
  tree-sitter docs show.
• Theme scopes are theme-specific. A query can match a node perfectly and
  still show no color if your theme doesn't style that scope. Use the Syntax
  Inspector to confirm both the matched scope and whether the theme paints it.
• The Library requires a universal binary. Submission rejects an
  arm64-only dylib; compile with -arch arm64 -arch x86_64.

License

MIT. See LICENSE. Bundled grammar is MIT, see LICENSES/.

Changelog

All notable changes to this extension are documented here.

1.0 — Initial release

• Tree-sitter based syntax highlighting for HAML templates
• Tags, classes, IDs, attribute hashes, doctypes, comments, and filters
• Embedded Ruby highlighted via injection into Nova's built-in Ruby grammar
• Ruby interpolation in text and attributes
• ⌘/ comment toggling using HAML's silent -# comment