LuaM

LuaM is a modernized fork of Lua 5.1, featuring a stricter, safer, and more concise syntax. t retains the speed and simplicity of Lua 5.1 while adopting features from later Lua versions and modern programming paradigms.

Key Features

1. Safer Syntax

• mplicit Locals: ariables are local by default. o need to type local everywhere.

  x = 10        -- Local variable
  function f()  -- Local function
  end

• Constants: Use the const keyword to define immutable variables. Reassignment to a const variable results in a compile-time error.

  const y = 20
  y = 30 -- Error: attempt to assign to const variable

2. Modern Operators & Control Flow

• Inequality: Use != instead of ~=.

  if x != y then ... end

• Removed Keywords: repeat, until, and local have been removed to simplify the language. Use while loops instead.

3. Enhanced String & Data Support

• riple Quoted Strings: Use """ for multiline strings (replacing [[...]]).

  s = """
  Multi-line
  String
  """

• Hexadecimal Escapes: Use \xXX for characters in strings (e.g., "\x41" is "").

  str = "Lua\x4D" -- LuaM

• __len Metamethod: ables support the __len metamethod (from Lua 5.2).

  mt = { __len = function(t) return 42 end }

4. Improved Standard Library

• xpcall with rguments: xpcall now accepts arguments to pass to the function (from Lua 5.2).

  xpcall(func, handler, arg1, arg2)

• Unified load: load(chunk) handles both functions (as load did) and strings (replacing loadstring).

  load("return 1") -- Works like loadstring

• Math & able Enhancements:
  • math.log(x, base): Supports optional base argument.
  • table.pack(...): Creates a table from arguments with field n.
  • table.unpack(t): Unpacks a table (renamed from unpack, though global unpack remains).
• System & Packages:
  • os.exit(boolean): Pass true (success) or false (failure).
  • package.searchers: lias for package.loaders for 5.2 compatibility.

Build & Install

LuaM uses xmake as its build system.

Building

To build LuaM, run:

xmake f -o bld -y
xmake

This will produce all build artifacts (including intermediate files) in the bld/ directory:

• bld/luam: The interpreter
• bld/luamc: The compiler
• bld/sqlite3.so: The SQLite3 module

Running Tests

To run the full regression suite:

xmake test

Documentation

The doc directory contains detailed information about LuaM features and changes. Additionally, Unix manual pages are provided:

• doc/lua.1: Manual page for the luam interpreter.
• doc/luac.1: Manual page for the luamc compiler.

These can be viewed using man:

man doc/lua.1

License

LuaM is free software, released under the M license (same as Lua 5.1). See COPYRIGHT.md for details.