Attempt to make a statically typed language that compiles to Lua. It's still messy, missing important features, and likely to have bugs.

In addition to static types, it also has syntax that treats everything as an expression, and supports pass-by-value structures that are stored with multiple local variables to avoid allocating/collecting tables.

Some features that are missing (and i'm not sure how to implement) include class/struct methods (including operators), modules and multiple file support, access to standard library, and allowing recursive functions.

To use it, run main.lua with the path a source code file as a command-line arg.

Example code:

# tuple
var t = (1, 2);

# define a structure stored with a table
class MyObj (a: (float, string), b: bool);

var o = new MyObj {a = (123, "test"), b = false};

o.b = true;

o.a._1 = 321;

t._2 = o.a._1;

t._1 = if (o.b) (
   456
) else (
   789
);

# similar to class, but stored with multiple locals instead of a table
struct Vec2 (x: float, y: float);

# function (return type inferred)
var vec2_new = fn (x: float, y: float) (
    new Vec2 {x = x, y = y} # missing ; causes the value to be returned
);

# function (explicit return type)
var vec2_add = fn (a: Vec2, b: Vec2 -> Vec2) (
    new Vec2 {x = a.x + b.x, y = a.y + b.y}
);

var a = vec2_new(1, 2);

var b = vec2_new(5, 6);

var c = vec2_add(a, b);

var d = vec2_add(vec2_add(b, c), vec2_new(3, 4));
 
variant V (
	a (string, string),
	b (float, string),
	c,
	d bool
);

let f = fn(v: V) ();

let x = new V.b((5, "asdf"));

f(x);
f(new V.d(true));
f(new V.c());

Example output:

 local ____tmp_0,____tmp_1=(1),(2);




 local o=({(123),"test",(false),});

o[3]=(true);

o[1]=(321);____tmp_1=

o[1]; do  local ____tmp_20;





 if o[3] then ____tmp_20=(456) else ____tmp_20=(789) end ;____tmp_0=____tmp_20 end ;







 local vec2_new=(function(x,y) return x,y end);




 local vec2_add=(function(____tmp_2,____tmp_3,____tmp_4,____tmp_5) return (____tmp_2 + ____tmp_4),(____tmp_3 + ____tmp_5) end);

 local ____tmp_6,____tmp_7=vec2_new((1),(2));

 local ____tmp_8,____tmp_9=vec2_new((5),(6));

 local ____tmp_10,____tmp_11=vec2_add(____tmp_6,____tmp_7,____tmp_8,____tmp_9); local ____tmp_12,____tmp_13; do  local ____tmp_21,____tmp_22=

vec2_add(____tmp_8,____tmp_9,____tmp_10,____tmp_11);____tmp_12,____tmp_13=vec2_add(____tmp_21,____tmp_22,vec2_new((3),(4))) end ;








 local f=(function(____tmp_14,____tmp_15,____tmp_16) end);

 local ____tmp_17,____tmp_18,____tmp_19=(2),(5),"asdf";

f(____tmp_17,____tmp_18,____tmp_19);
f((4),(true),(nil));
f((3),(nil),(nil))