VS Code Extension

The Rumoca Modelica extension provides language support (diagnostics, completion, hover, semantic highlighting), simulation commands, scenario settings, and result viewers — all inside VS Code.

Install it from the marketplace. It bundles a rumoca-lsp language server, so no separate install is needed. To use your own server build instead (for compiler development), enable rumoca.useSystemServer and put rumoca-lsp on PATH.

Modelica Source Roots

Modelica package paths for a workspace are configured with rumoca-workspace.toml.

Place the file at the workspace root, or in a subdirectory when the roots only apply below that directory:

source_roots = [
  "../target/msl/ModelicaStandardLibrary-4.1.0",
  "../target/cmm/CMM-a642c381",
]

The Rumoca repository examples include examples/rumoca-workspace.toml. Run cargo xtask repo modelica-deps ensure first so those target directories exist.

Settings Panel

Open Rumoca settings from the toolbar or command palette (Open Rumoca Settings). Shared package roots belong in rumoca-workspace.toml; Scenario Source Root Paths edits the active rumoca-scenario.toml for paths that only apply to that one configured run.

The picker stores workspace-relative paths whenever the selected folder is inside the workspace.

Inlay Hints

Array-dimension hints (for example [2x3] after a component name) are always shown. Parameter-name hints, which label call arguments with the callee’s parameter names, are controlled by rumoca.inlayHints.parameterNames and are off by default. Set it to one of:

none (default): no parameter-name hints.
userFunctions: hints only for calls to user-defined functions, using each function’s declared parameter names.
all: hints for user-defined functions and for known builtin functions.

Single-argument calls (such as der(x)) never receive a parameter-name hint, and each hint is anchored at the start of the full argument, including any leading unary operator. Changing the setting takes effect after the language server restarts.

Running Models

Run actions operate on rumoca-scenario.toml scenario files. The extension contributes rumoca-scenario.toml as a TOML language extension, so normal TOML editor features attach while Rumoca still activates for rumoca-scenario.toml and .mo files. Use Create Rumoca Scenario to generate a rumoca-scenario.toml for a model; the runnable source of truth is always the scenario file.

For interactive examples, open the rumoca-scenario.toml scenario, then use Play. For batch simulation, the results panel opens inside VS Code.

Command	Purpose
Create Rumoca Scenario	Generate a `rumoca-scenario.toml` next to a model
Run Current Rumoca Scenario	Compile and simulate the active scenario
Open Scenario Settings	Edit the active scenario’s settings
Open Rumoca Settings	Extension settings menu
Open Rumoca User Guide	This book
Open Rumoca Dev Guide	The contributor book
Toggle / Expand All / Collapse All Annotation Expansion	Control inline annotation rendering

Diagnostics

Compiler and simulation diagnostics are reported to the Problems panel when a source span is available. CLI output uses rich terminal diagnostics; VS Code diagnostics use the raw file/range information without terminal wrappers.

Compile and instantiate errors appear in the Problems panel as well, not only in the compile-status lens above a model. When a model fails its full compile because a component’s class cannot be instantiated, the error is anchored at the enclosing model or class name in your open document, and the originating library location is included in the diagnostic message so the detail is not lost. This means the failure you would otherwise see only when simulating is now visible as a squiggle while you edit.

Documentation Access

The user guide and the contributor guide are available directly from the command palette (Open Rumoca User Guide / Open Rumoca Dev Guide Guide), so you do not need to hunt for URLs. The same live-example pages work in any browser.

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