EVM in EVM

evm.js

contract EVM {
    struct VMState {
        uint[1024] stack;
        uint stackHeight;
        bytes bytecode;
        uint pc;
        uint[] mem;
    }
    function step(VMState _state) internal returns (bool)
    {
        if (_state.pc >= _state.bytecode.length) return false;
        byte instr = _state.bytecode[_state.pc];
        if (instr == 0x00) // STOP
            return true;
        else if (instr == 0x01) // ADD
        {
            if (_state.stackHeight < 2) return false;
            _state.stack[_state.stackHeight - 2] = _state.stack[_state.stackHeight - 1] + _state.stack[_state.stackHeight - 2];
            _state.stackHeight--;
            _state.pc++;
        }
        else if (instr == 0x02) // MUL
        {
            if (_state.stackHeight < 2) return false;
            _state.stack[_state.stackHeight - 2] = _state.stack[_state.stackHeight - 1] * _state.stack[_state.stackHeight - 2];
            _state.stackHeight--;
            _state.pc++;
        }
        //...
        
    }
}