effect-sugar

Effect Sugar VSCode Extension

Provides syntax highlighting and TypeScript error suppression for Effect-TS gen blocks.

Features

• Syntax highlighting for gen { } blocks and <- operator
• TypeScript error suppression inside gen blocks (via TS plugin)
• Code actions explaining suppressed errors

Installation

Development Installation

• Install dependencies:

  cd packages/effect-sugar/vscode-extension
  npm install
  

• Compile the extension:

  npm run compile
  

• Open VSCode and press F5 to launch the Extension Development Host

TypeScript Plugin Setup

To enable error suppression, add the TypeScript plugin to your tsconfig.json:

{
  "compilerOptions": {
    "plugins": [
      { "name": "effect-sugar-ts-plugin" }
    ]
  }
}

Then tell VSCode to use the workspace TypeScript version:

• Open Command Palette (Cmd+Shift+P)
• Run "TypeScript: Select TypeScript Version"
• Choose "Use Workspace Version"

Usage

Files with .gen.ts extension will automatically use the Effect Sugar language mode.

For regular .ts files, the syntax injection grammar will highlight gen blocks.

Example

// This will be highlighted and errors suppressed
const program = gen {
  user <- getUser(id)
  profile <- getProfile(user.id)
  return { user, profile }
}

Configuration

Setting	Default	Description
effectSugar.suppressDiagnostics	true	Suppress TypeScript diagnostics inside gen blocks

How It Works

• TextMate Grammar: Provides syntax highlighting for gen, <-, and variable bindings
• Injection Grammar: Highlights gen blocks in regular .ts/.tsx files
• TypeScript Plugin: Hooks into the language service to filter diagnostics

Known Limitations

• Full type inference inside gen blocks requires the build transformation to run
• Hover information shows raw syntax, not inferred types
• Go-to-definition for bound variables doesn't work inside gen blocks

Development

# Install dependencies
npm install

# Compile
npm run compile

# Watch mode
npm run watch

# Package extension
npm run package

Roadmap

• Semantic token provider for better highlighting
• Hover information showing transformed code
• Go-to-definition support for bound variables
• Auto-complete for Effect methods