Rumoca Modelica

A VS Code extension providing language support for Modelica using the rumoca compiler.

Features

• Syntax highlighting for Modelica files (.mo)
• Real-time diagnostics - errors and warnings as you type
• Autocomplete for Modelica keywords and built-in functions
• Hover information for keywords and types
• Go to definition for variables and classes
• Document symbols - file outline with classes, components, equations
• Signature help - function parameter hints
• Find references - locate all uses of a symbol
• Code folding - collapse classes, equations, comments
• Formatting - auto-format Modelica code
• Inlay hints - inline parameter names and array dimensions
• Semantic tokens - enhanced syntax highlighting
• Code lens - reference counts and navigation
• Document links - clickable URLs and file paths

Installation

From VS Code Marketplace (recommended):

Search for "Rumoca Modelica" in the VS Code Extensions view (Ctrl+Shift+X / Cmd+Shift+X) and install.

The extension includes a bundled rumoca-lsp language server, so no additional installation is required for most users.

From VSIX file:

1. Download the .vsix file for your platform from GitHub Releases
2. In VS Code, open the Command Palette (Ctrl+Shift+P / Cmd+Shift+P)
3. Run "Extensions: Install from VSIX..."
4. Select the downloaded .vsix file

Using a Custom/System Server

If you want to use a different version of rumoca-lsp (e.g., a development build), you have two options:

Option 1: Use System Server

Set rumoca.useSystemServer to true in your VS Code settings. The extension will then search for rumoca-lsp in your PATH or ~/.cargo/bin/.

{
  "rumoca.useSystemServer": true
}

Option 2: Specify Custom Path

Set rumoca.serverPath to the full path of your custom rumoca-lsp binary:

{
  "rumoca.serverPath": "/path/to/custom/rumoca-lsp"
}

Installing rumoca-lsp Manually

If you need to install rumoca-lsp manually:

# From crates.io
cargo install rumoca

# Or from source
git clone https://github.com/cognipilot/rumoca.git
cd rumoca
cargo install --path .

Configuration

Configuring Library Paths

To use external Modelica libraries (like the Modelica Standard Library), configure the rumoca.modelicaPath setting with the directories containing your libraries:

{
  "rumoca.modelicaPath": [
    "/path/to/ModelicaStandardLibrary",
    "/path/to/other/library"
  ]
}

These paths are added to the MODELICAPATH used for import resolution. Paths configured here take priority over the MODELICAPATH environment variable.

Example workspace configuration (.vscode/settings.json):

{
  "rumoca.modelicaPath": [
    "${workspaceFolder}/../ModelicaStandardLibrary"
  ]
}

Note: The MODELICAPATH environment variable is also supported. If set before starting VS Code, those directories will be searched in addition to paths configured in settings.

Troubleshooting

Extension shows "Using system-installed rumoca-lsp" warning:

This means the bundled binary wasn't found (possibly a platform mismatch). You can:

1. Set rumoca.useSystemServer to true to suppress the warning
2. Install rumoca-lsp manually (see above)

Extension can't find rumoca-lsp:

1. The extension will prompt you to install via cargo
2. Or set rumoca.serverPath to the full path of your rumoca-lsp binary

Debug logging:

To see detailed logs, enable debug mode in settings:

{
  "rumoca.debug": true
}

Then check the "Rumoca Modelica" output channel in VS Code.

Building the Extension from Source

# Build the LSP server
cargo build --release

# Build the extension
cd editors/vscode
npm install
npm run compile
npx @vscode/vsce package
code --install-extension rumoca-modelica-*.vsix

License

Apache-2.0