MeTTa Language Support for VS Code
Full-featured language support for the MeTTa programming language, powered by a Tree-sitter parser and the Language Server Protocol.
Features
| Feature |
Description |
| Diagnostics |
Real-time syntax error detection and arity validation via Tree-sitter AST analysis |
| Completions |
Context-aware completions for builtins, keywords, and user-defined symbols |
| Hover |
Documentation on hover for all MeTTa builtins and user definitions |
| Go-to-Definition |
Jump to the definition of any user-defined function or variable |
| Document Symbols |
Outline view of all definitions in the current file |
| Workspace Symbols |
Search for symbols across all open MeTTa files |
| Folding |
Code folding for multi-line S-expressions |
| Code Actions |
Quick-fixes for mismatched parentheses and brackets |
Supported File Types
Requirements
- VS Code 1.75.0 or later
- Node.js 18 or later
Extension Settings
| Setting |
Type |
Default |
Description |
metta.server.debug |
boolean |
false |
Enable debug logging |
metta.server.trace |
string |
"off" |
Trace level: off, messages, or verbose |
Commands
| Command |
Description |
MeTTa: Restart MeTTa Language Server |
Restart the language server |
Architecture
This extension uses a client/server architecture:
- Client: VS Code extension that launches and communicates with the server
- Server: LSP server using Tree-sitter for parsing and AST-based analysis
- Grammar: Tree-sitter grammar for MeTTa (
tree-sitter-metta)
All analysis (diagnostics, symbol extraction, folding) is driven by the Tree-sitter AST — no regex-based parsing.
Development
# Install dependencies
npm install
# Build both client and server
npm run build
# Watch mode
npm run watch
License
MIT
| |
