YAMMM Language Support for VS Code

This extension provides language support for YAMMM (Yet Another Meta-Meta Model) schema files.

Features

• Syntax Highlighting: Full TextMate grammar for .yammm files
• IntelliSense: Completions for keywords, types, and snippets
• Diagnostics: Real-time error checking as you type
• Go to Definition: Navigate to type definitions
• Hover Information: View type details and documentation
• Document Symbols: Outline view and breadcrumbs
• Formatting: Automatic code formatting
• Snippets: Quick templates for common patterns
• Markdown Embedded Blocks: Full language support for yammm code blocks in Markdown files

Markdown Support

YAMMM code blocks in Markdown files receive full language support:

• Syntax highlighting via TextMate injection grammar
• Real-time diagnostics (parse errors, semantic errors)
• Hover information with type details
• Completions for keywords, types, and snippets
• Go-to-definition for type references
• Document symbols for outline and breadcrumbs

Each code block is analyzed independently as a standalone schema. Use fenced code blocks with the yammm language identifier:

```yammm
schema "example"

type Person {
    id String primary
    name String required
}
```

Limitations: Imports are not supported in markdown blocks (produces a diagnostic). Formatting is disabled for markdown files. Code blocks are analyzed in isolation with no cross-block references. Files must use .yammm, .md, or .markdown extensions to receive LSP support — manually setting a file's language in VS Code (e.g., on a .txt file) does not activate LSP features; rename the file to use a supported extension.

Requirements

The extension requires the yammm-lsp language server binary. You can either:

1. Use bundled binary: The extension includes pre-built binaries for common platforms
2. Configure custom path: Set yammm.lsp.serverPath in settings

Extension Settings

• yammm.lsp.serverPath: Path to the yammm-lsp binary (optional)
• yammm.lsp.logLevel: Log level for the language server (error, warn, info, debug, trace)
• yammm.lsp.moduleRoot: Override the module root for import resolution
• yammm.trace.server: Trace communication between VS Code and the server

Supported Platforms

Pre-built binaries are included for:

• macOS (Apple Silicon / arm64)
• macOS (Intel / amd64)
• Linux (amd64)
• Linux (arm64)
• Windows (amd64)
• Windows (arm64)

Snippets

Development

Requires Node.js >= 20 (pinned in .nvmrc).

# Install dependencies
npm install

# Compile TypeScript
npm run compile

# Run grammar snapshot tests
npm run test:grammar

# Package extension
npm run package

License

MIT