BadgerScript

A toy language written in C.

Test with:

$ make
$ src/fh tests/test.fh

Features

The code implements a pretty simple and fast register-based VM. Script execution has 3 phases:

• lexing/parsing converts text to an abstract syntax tree (AST)
• compilation converts the AST to bytecode
• execution runs the bytecode in the VM

There's currently no garbage collection, so the only full first class data type is number. Strings are supported, but they can't be dynamically created or modified.

The language is dynamically-typed with mandatory variable declarations, while loops, if/else and blocks with lexical scope.

Status

Feature	Status
Parsing to AST	Works
Bytecode compilation	Works
VM (bytecode execution)	Works
Garbage collection	TODO

TODO

There's a lot of stuff that's not hard to do but would require some kind of garbage collection to be useful. Current plans are:

1. mark-and-sweep garbage collection
2. dynamic creation of strings
3. map and vector values
4. closures

Example Code

function calc_point(cx, cy, max_iter)
{
    var i = 0;
    var x = 0;
    var y = 0;
    while (i < max_iter) {
        var t = x*x - y*y + cx;
        y = 2*x*y + cy;
        x = t;
        if (x*x + y*y > 4)
            break;
        i = i + 1;
    }
    return i;
}

function mandelbrot(x1,y1, x2,y2, size_x,size_y, max_iter)
{
    var step_x = (x2-x1)/size_x;
    var step_y = (y2-y1)/size_y;

    var y = y1;
    while (y <= y2) {
        var x = x1;
        while (x <= x2) {
            var c = calc_point(x, y, max_iter);
            if (c == max_iter)
                printf(".");
            else
                printf("%d", c%10);
            x = x + step_x;
        }
        y = y + step_y;
        printf("\n");
    }
}

function main()
{
  mandelbrot(-2, -2, 2, 2, 200, 54, 1500);
}

License

MIT License (LICENSE)