gua

go+lua=gua (experimental programming language)

WAT

transpiler from gua:

Example

std := _G
setmt := std.setmetatable

Type := {}
func (t Type) __call(x) {
    x = x || {}
    x.__index = x
    return setmt(x, t)
}
setmt(Type, Type)

Color := Type([0, 0, 0])

func (c Color) __tostring() {
    return std::string::format("[%d, %d, %d]", c[1], c[2], c[3])
}

Point := Type({
    x: 0,
    y: 0,
    c: nil,
})

func (p Point) move(dx, dy) {
    p.x += dx
    p.y += dy
}

func (p Point) __tostring() {
    return std::string::format("x: %d, y: %d, c: %s", p.x, p.y, std::tostring(p.c))
}

p := Point({
    x: 10,
    y: 10,
    c: Color(),
})

p.c[1] = 255

for p.x < 20 {
    p.move(1, 0)
}

std::print(p)

to lua:

Example

local std = _G
local setmt = std.setmetatable
local Type = {}
function Type:__call(x)
    local t = self
    x = x or {}
    x.__index = x
    return setmt(x, t)
end
setmt(Type, Type)
local Color = Type({0, 0, 0})
function Color:__tostring()
    local c = self
    return std.string.format("[%d, %d, %d]", c[1], c[2], c[3])
end
local Point = Type({
    x = 0;
    y = 0;
    c = nil;
})
function Point:move(dx, dy)
    local p = self
    p.x = p.x + dx
    p.y = p.y + dy
end
function Point:__tostring()
    local p = self
    return std.string.format("x: %d, y: %d, c: %s", p.x, p.y, std.tostring(p.c))
end
local p = Point({
    x = 10;
    y = 10;
    c = Color();
})
p.c[1] = 255
while p.x < 20 do
    p:move(1, 0)
end
std.print(p)

HOWTO

• run gua:

$ lua gua.lua example.gua

• transpile to lua:

$ lua gua.lua example.gua example.lua

FEATURES

• go-style syntax
• go-style if
• go/lua-style for
• js-style map/list literals
• switch without break
• const
• continue
• global variables are prohibited except for _G
• shadowing of variable is prohibited
• . instead of : for method calls with self
• :: instead of . for method calls without self (like namespaces)
• only " for strings