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.

For Linux release builds, the bundled rumoca-lsp is shipped as a musl-linked binary for both linux-x64 and linux-arm64. This is intentional: it reduces breakage from remote-host glibc version mismatches.

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 GitHub Releases installer
curl --proto '=https' --tlsv1.2 -LsSf https://raw.githubusercontent.com/cognipilot/rumoca/main/install/install.sh | bash -s -- --with-lsp

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

Configuration

Configuring Source Root Paths

To use external Modelica packages like the Modelica Standard Library, configure the rumoca.sourceRootPaths setting with the directories containing those source roots:

{
  "rumoca.sourceRootPaths": [
    "/path/to/ModelicaStandardLibrary",
    "/path/to/other/source-root"
  ]
}

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

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

{
  "rumoca.sourceRootPaths": [
    "${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 or could not execute on your machine. You can:

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

Extension shows a glibc/loader error for the bundled server:

The extension now probes the bundled rumoca-lsp before startup and will fall back to a system-installed server if one is available. If you still hit this case:

1. update to the latest extension release
2. install rumoca-lsp manually and set rumoca.useSystemServer to true
3. report the failing platform/host details if the latest bundled Linux build still does not run

Extension can't find rumoca-lsp:

1. Install rumoca-lsp with the GitHub Releases installer shown above
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

# one-time bootstrap from repo root
cargo run --bin rum -- repo cli install

# run the extension verification gate
rum vscode test

# build/package/install the extension locally
rum vscode build

# package a target-specific VSIX with bundled release binaries
rum vscode package --target linux-x64

# development loop with watch mode + Extension Development Host
rum vscode edit

rum vscode package is the maintainer path for release-style VSIX artifacts. On Debian/Ubuntu, you can let it install musl-tools on the first Linux packaging run:

rum vscode package --target linux-x64 --install-musl-tools

If you need the lower-level manual steps, rum vscode build and rum vscode package wrap the same TypeScript, Cargo, and VSIX packaging flow that lives under editors/vscode/.

License

Apache-2.0