eatonphil / jsc

A JavaScript compiler written in TypeScript targeting C++/V8

Javascript compiler targeting C++/V8

Building

Requires Node.

$ yarn

Example

$ yarn tsc
$ node build/jsc.js tests/tco.js
$ node bin/index.js
12586269025

Features

• Functions and function calls
  • Basic tail-call optimization
• Var, const, let declarations
• For, do, while statements
• Basic primitive operations
• Basic import support
• Number, string, boolean and null literals
• Basic value unboxing

Not (yet) supported

• Prototype functions
• Nested functions
• Closures
• And much, much more!

Code produced

The following:

function fib(n: number, a: number, b: number) {
    if (n == 0) {
        return a;
    }

    if (n == 1) {
        return b;
    }

    return fib(n - 1, b, a + b);
}

Gets compiled to:

void tco_fib(const FunctionCallbackInfo<Value> &args) {
  Isolate *isolate = args.GetIsolate();
  double tco_n = toNumber(args[0]);
  double tco_a = toNumber(args[1]);
  double tco_b = toNumber(args[2]);

tail_recurse_1:

    ;

  bool sym_if_test_58 = (tco_n == 0);
  if (sym_if_test_58) {
    args.GetReturnValue().Set(Number::New(isolate, tco_a));
    return;
  }

  bool sym_if_test_70 = (tco_n == 1);
  if (sym_if_test_70) {
    args.GetReturnValue().Set(Number::New(isolate, tco_b));
    return;
  }

  Local<Value> sym_arg_83 = Number::New(isolate, (tco_n - 1));
  Local<Value> sym_arg_92 = Number::New(isolate, (tco_a + tco_b));
  tco_n = toNumber(sym_arg_83);
  tco_a = tco_b;
  tco_b = toNumber(sym_arg_92);
  goto tail_recurse_1;
}