Mah Language for VS Code

Editor support for Mah (.mh files):

• Syntax highlighting (a TextMate grammar covering Mah's keywords, structs/enums, async (detach/.await/sleep_async), strings, numbers, and comments)
• Full language server support via mah lsp:
  • diagnostics
  • hover — including doc comments, and struct/enum/variant shapes
  • go-to-definition — variables, functions, struct/enum/variant names, and jumping straight into an imported file
  • rename — including across files (renaming a function/variable updates every file in the workspace that imports it), and struct/enum type, variant, and field names
  • completion — keywords, builtins, in-scope symbols, namespaced imports, and .mh file paths and std: modules (std:math, ...) while typing inside an import "..." string
• A custom file icon for .mh files in the Explorer (VS Code's built-in icon themes only — see File icon note below if you use a third-party icon theme)

Requirements

The mah CLI must be installed and on PATH. From the root of the mahlang repo:

make install-mah

This installs mah (see ../../Makefile), which the extension spawns as mah lsp to talk LSP over stdio — the same server used by the Neovim integration (editors/nvim), just launched by VS Code instead.

If mah isn't on PATH, or you want to point at a specific build, set:

{ "mah.serverPath": "/absolute/path/to/mah" }

Building and running locally (not yet published to the Marketplace)

From this directory:

npm install
npm run compile

Then either:

• Press F5 in VS Code (with this folder open) to launch an Extension Development Host with the extension loaded, or

• Package a .vsix and install it manually:

  npx @vscode/vsce package
  code --install-extension mah-language-0.3.0.vsix
  

  (Also available as make build-vscode from the repo root.)

File icon note

VS Code lets a language extension register a per-language file icon (contributes.languages[].icon), which this extension does. It's shown by VS Code's own built-in icon themes (e.g. "Seti (Visual Studio Code)"), but popular third-party icon themes maintain their own language→icon tables and don't read this field automatically:

• vscode-icons: no built-in Mah icon yet; a PR to vscode-icons/vscode-icons adding the mah language ID would be the proper way to get one upstream.

• Material Icon Theme: you can self-configure a mapping in your settings:

  "material-icon-theme.languages.associations": { "mah": "python" }
  

  (swap "python" for whichever bundled icon you'd like used in the meantime).