Command-line interface for the Lua 5.4 interpreter implemented in MoonBit.

moon build

moon run cmd -- [OPTIONS] [SCRIPT] [ARGS...]

Backend/I/O

• Preferred target is js (see moon.mod.json).
• CLI file I/O uses synchronous Node bindings via mizchi/js/node/fs (js.mbt), e.g. @fs.read_file_as_string(path).
• Reference: https://github.com/mizchi/js.mbt

• -v - Show version information
• -i - Enter interactive mode after executing script
• -E - Ignore environment variables
• -W - Turn warnings into errors

• -e <code> - Execute a string of Lua code
• -l <library> - Load a library (can be specified multiple times)

• SCRIPT - Lua script file to execute
• ARGS... - Arguments passed to the script

moon run cmd -- -v

Output:

Lua 5.4.0  Copyright (C) 1994-2020 Lua.org, PUC-Rio
MoonBit port Copyright (C) 2025

moon run cmd -- -e "print('Hello, Lua!')"

moon run cmd -- -l math -l string

moon run cmd -- myscript.lua arg1 arg2 arg3

moon run cmd -- -i -e "x = 10"

moon run cmd -- -E -W

The CLI framework is complete and all command-line parsing works correctly. The following features are pending implementation:

• Actual Lua code execution (requires lua/api implementation)
• Interactive REPL (requires lua/api and lua/vm implementation)
• Library loading (requires lua/stdlib implementation)
• Script file reading and execution

All command-line options are parsed and ready to be connected to the Lua interpreter once the core components are implemented.

The CLI uses the clap.mbt library for command-line argument parsing, which provides:

• Robust argument validation
• Automatic help generation
• Support for flags, named arguments, and positional arguments
• Error handling with descriptive messages

The implementation follows standard Lua command-line conventions and is compatible with Lua 5.4's CLI interface.