Funcs -> Stack Machine

// Functions:

function a(x, y, z) {
  x[y] = z;
}
function b(x, p) {
  for (let i in p) a(x, i, p[i]);
}
function c() {
  let x = { foo: 'bar' };
  b(x, { foo: 1, bar: 2 });
}


// Stack Machine:

const OP_A = 1;
const OP_B = 2;
const OP_C = 3;
let firstOp;
let lastOp;
function op(op, obj, param, data) {
  const c = { op, obj, param, data: next: undefined };
  if (lastOp) lastOp.next = c;
  else { firstOp = lastOp = c; run(); }
}
function run() {
  while (firstOp) {
    const { obj, param, data } = firstOp;
    switch (firstOp.op) {
      case OP_A:
        obj[param] = data;
        break;
      case OP_B:
        for (let i in param) op(OP_A, obj, i, param[i]);
        break;
      case OP_C: {
        let obj = {};
        op(OP_B, obj, { foo: 1, bar: 2 });
        break;
      }
    }
    firstOp = firstOp.next;
  }
}
op(OP_C); // start!