AppliedML LSP for Visual Studio Code

Language support for Applied Meta Language (AppliedML), powered by amlc-lsp. The extension recognizes .aml files, provides basic TextMate highlighting, and exposes the diagnostics and language features advertised by the server.

Server setup

The extension starts amlc-lsp from PATH by default. If that fails, it checks the active OPAM switch for an existing server. When the switch already contains the compatible amlc.0.1.0~preview package but not the server, choose Install with OPAM in the notification or run AppliedML: Install Language Server with OPAM. After confirmation, the extension installs only amlc-lsp.0.3.0 from its immutable release commit and reconnects automatically. It neither installs nor replaces AMLC.

The installer requires OPAM and AMLC to be available in the same active switch. It stops with guidance when OPAM is unavailable, AMLC is absent, or the AMLC version is incompatible. Set AppliedML › Opam: Path if the OPAM executable is not named opam or is outside Visual Studio Code's PATH.

Nix and manual server installations remain supported. Follow the server installation guide, then set AppliedML › Server: Path to the absolute amlc-lsp executable if Visual Studio Code cannot find it. On Windows, select amlc-lsp.exe. The extension does not bundle the compiler or language server.

Use AppliedML: Show Server Information from the Command Palette to inspect the executable and connected version. The extension warns when the server uses a different major.minor release line.

Features

Compiler-backed diagnostics and completion
Hover, signature help, and symbol navigation
References and guarded rename
Quick fixes and indentation formatting
Semantic tokens, folding, and selection ranges

Exact behavior and cross-file limits are documented in the server README.

Settings

Setting	Purpose
`amlcLsp.server.path`	Absolute server path; empty searches `PATH`
`amlcLsp.server.arguments`	Additional server arguments
`amlcLsp.server.environment`	Environment variables added to the server process
`amlcLsp.opam.path`	OPAM executable used to find or install the server
`amlcLsp.dialect`	`auto`, `appliedml`, or `legacy` syntax selection
`amlcLsp.trace.server`	LSP message tracing in the AppliedML output channel

Changes to the server or OPAM path, arguments, or environment restart the server automatically. The AppliedML: Restart Language Server command remains available for manual recovery.

Privacy and workspace support

Analysis runs locally. This extension does not send source code or telemetry to Arkenstone Labs. Because it starts a local executable and requires ordinary files, it is disabled for untrusted and virtual workspaces. Remote SSH, WSL, and Codespaces run the extension and server in the remote workspace environment.

Development

cd vscode
npm ci
npm run compile
code --extensionDevelopmentPath="$PWD"

Run npm test for the Extension Host integration test. It downloads VS Code 1.100.0 into the ignored .vscode-test directory and verifies activation, diagnostics, completion, automatic restart, and version compatibility.

AppliedML LSP