ceph/src/boost/libs/spirit/example/x3/calc/calc7/vm.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2014 Joel de Guzman
   3
   4     Distributed under the Boost Software License, Version 1.0. (See accompanying
   5     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 =============================================================================*/
   7 #if !defined(BOOST_SPIRIT_X3_CALC7_VM_HPP)
   8 #define BOOST_SPIRIT_X3_CALC7_VM_HPP
   9
  10 #include <vector>
  11
  12 namespace client
  13 {
  14     ///////////////////////////////////////////////////////////////////////////
  15     //  The Virtual Machine
  16     ///////////////////////////////////////////////////////////////////////////
  17     enum byte_code
  18     {
  19         op_neg,     //  negate the top stack entry
  20         op_add,     //  add top two stack entries
  21         op_sub,     //  subtract top two stack entries
  22         op_mul,     //  multiply top two stack entries
  23         op_div,     //  divide top two stack entries
  24         op_int,     //  push constant integer into the stack
  25     };
  26
  27     class vmachine
  28     {
  29     public:
  30
  31         vmachine(unsigned stackSize = 4096)
  32           : stack(stackSize)
  33           , stack_ptr(stack.begin())
  34         {
  35         }
  36
  37         int top() const { return stack_ptr[-1]; };
  38         void execute(std::vector<int> const& code);
  39
  40     private:
  41
  42         std::vector<int> stack;
  43         std::vector<int>::iterator stack_ptr;
  44     };
  45
  46 }
  47
  48 #endif