Callisto

Callisto is a superset of Lua that transpiles straight down to regular Lua.

Callisto supports the following platforms:

• Lua 5.1, 5.2, and 5.3
• LuaJIT

Features

• Bang variables - object:bang!() (object:bangBANG() or object:bangInPlace() in legacy mode)
• Que variables - object:what?() (object:whatQUE())
• Increment operator - number++ (legacy mode only)
• Mutating operators
  • a += b
  • a -= b
  • a *= b
  • a /= b
  • a ^= b
  • a ..= b
• Compound named array lookups
  • vec->xyz translates to vec[1], vec[2], vec[3]
  • Supports the following sets of lookups; can be mixed:
    • (x, y, z, w)
    • (r, g, b, a)
    • (s, t, p, q) (legacy mode only)
    • (u, v) (legacy mode only)
• Fat-arrow lambdas - (x) => x^2
• Default function arguments - function(x = 5) return x^2 end

Usage

Callisto exposes the compiler interface through the callisto commmand line tool and through the Lua compiler API.

Command Line

The command line can be invoked in two ways:

• Through an executable generated through build.bat or build.sh (requires srlua)
• Directly from the Lua source

Command line:

# outputs to file.lua
callisto file.clua

# outputs to other.lua
callisto file.clua -o other.lua

Directly from Lua source:

#outputs to file.lua
luajit tools/callisto.lua file.lua

#outputs to other.lua
luajit tools/callisto.lua other.lua

Compiler API

local Callisto = require("Callisto")
local source = [[
	(x = 1) => x^2
]]

local source, sourcemap = Callisto.Transform(source)
local chunk, err = Callisto.LoadString(source, sourcemap)
if (not chunk) then
	error(err)
end

chunk()

-- OR

local chunk, err = Callisto.Compile(source)
if (not chunk) then
	error(err)
end

chunk()