lsp

GNN Language Server (LSP)

Overview

Minimal Language Server Protocol implementation for GNN files. Provides real-time diagnostics and hover information in editors that support LSP (VS Code, Neovim, etc.).

Requires: pygls package (pip install pygls)

Features

Feature	LSP Method	Description
Diagnostics on open	textDocument/didOpen	Validates sections, state-space, and connections
Diagnostics on save	textDocument/didSave	Re-validates after changes
Hover info	textDocument/hover	Shows variable dimensions and type on hover

Usage

# Start via CLI
gnn lsp

# Or directly
python -m src.lsp

VS Code Integration

Add to .vscode/settings.json:

{
  "gnn-lsp.server.path": "gnn",
  "gnn-lsp.server.args": ["lsp"]
}

Architecture

• Server: Built on pygls (Python Language Server framework)
• Validation: Delegates to gnn.schema (same validation as gnn validate)
• Hover: Parses state-space to show variable metadata at cursor position
• Fallback: Graceful degradation when pygls is not installed

File Structure

lsp/
├── __init__.py    # Server implementation (226 lines)
├── AGENTS.md      # Agent documentation
├── README.md      # This file
└── SPEC.md        # Module specification

References

• SPEC.md — Module specification
• AGENTS.md — Agent documentation