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 vmachine(unsigned stackSize=4096)31 vmachine(unsigned stackSize = 4096) 32 : stack(stackSize) 33 , stack_ptr(stack.begin()) 34 { 35 } 36 top() const37 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 49