Jac Development Tools

Jac Development Tools provides an end-to-end Jac editing workflow in VS Code.

Features

• Jac language registration for .jac files
• Syntax highlighting via TextMate grammar
• Fast diagnostics while typing
• Native validation on manual lint/transpile
• Jac-aware autocomplete (context-aware keywords, snippets, and member suggestions)
• Jac transpile command (jac2py with local fallback)
• Jac document formatting
• Jac playground panel
• Debug launch flow for generated Python output

Commands

Open the Command Palette and run:

• Jac: Lint Current File
• Jac: Transpile Current File
• Jac: Format Document
• Jac: Open Playground
• Jac: Debug Current File

Autocomplete notes:

• Only appears in valid Jac contexts such as top-level declarations, archetype bodies, walker entry blocks, graph expressions, imports, and member access chains
• Suggests local symbols from the current file, including node/walker/obj names, fields, and methods
• Includes starter snippets for with entry, def ... by llm, node, edge, walker, obj, enum, import from, include, impl, and match
• Native Jac execution is timeout-protected and output-capped so a slow or noisy local toolchain does not freeze the editor or flood memory

Requirements

• VS Code 1.85.0 or newer
• Optional: local Jac toolchain in workspace .venv for native check/transpile

If native Jac is unavailable, the extension uses local fallback logic for lint/transpile/format behavior.

Quick Start

1. Install the extension.
2. Open a .jac file in a workspace.
3. Run Jac: Lint Current File to validate code.
4. Run Jac: Format Document to normalize formatting.
5. Run Jac: Transpile Current File to generate Python under __jac_gen__.

Notes

• Diagnostics include code, location, source context, and fix suggestions.
• Formatting is local-first and normalizes indentation, delimiters, and statement endings.
• Prompt Visibility + Backboard (previous Phase 4 experiment) is currently rolled back and not part of this release scope.

License

MIT