Tessel for VS Code

Language support for Tessel, a small, Swift-like language for native apps and command-line programs.

Features

• Syntax highlighting for .tsl files.
• Errors as you type. The same errors tessel check reports, with their help text, appear as you edit, before you save, in the editor and in the Problems panel.
• Types on hover. Hover over an expression to see its type.
• Code completion. Fields and methods after value., enum cases after ., a module's public names after geometry., and every variable, function, type and view in scope. Typing . opens the list; Ctrl+Space asks for it anywhere.
• Run and build. The ▶ button in the editor's title bar runs the program (or with hot reload, from its menu), and the Command Palette has Tessel: Run Program, Run with Hot Reload, Check Program, Build App and Pin Tessel Version. They run tessel in a terminal.
• tessel.toml. With the Even Better TOML extension, a project's tessel.toml gets completion, descriptions and checking of its keys ([app], [[app.documents]], …). See The project file.
• The project's version of Tessel. When tessel.toml pins a version, errors and completion come from that version; the language server starts again when the file changes.
• Comment toggling, bracket matching, auto-closing pairs and indentation.

A program is a folder of .tsl files, and the whole folder is checked together, including the modules it imports. The run commands run the active file's folder when it has a main.tsl or a tessel.toml, and otherwise the file on its own.

Requirements

Errors, hover and completion come from the tessel command, which runs as a language server (tessel lsp). Install Tessel first; see Installation. Highlighting works without it.

Settings

In an untrusted workspace, highlighting works, and a folder's own tessel.path setting is ignored until you trust the folder.

Building from source

npm install
npm run package          # makes tessel-<version>.vsix
code --install-extension tessel-<version>.vsix