| /*============================================================================= |
| Copyright (c) 2001-2010 Joel de Guzman |
| |
| Distributed under the Boost Software License, Version 1.0. (See accompanying |
| file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| =============================================================================*/ |
| /////////////////////////////////////////////////////////////////////////////// |
| // |
| // Now we'll introduce variables and assignment. This time, we'll also |
| // be renaming some of the rules -- a strategy for a grander scheme |
| // to come ;-) |
| // |
| // This version also shows off grammar modularization. Here you will |
| // see how expressions and statements are built as modular grammars. |
| // |
| // [ JDG April 9, 2007 ] spirit2 |
| // |
| /////////////////////////////////////////////////////////////////////////////// |
| #include "calc6.hpp" |
| |
| template <typename Grammar> |
| bool compile(Grammar const& calc, std::string const& expr) |
| { |
| using ascii::space; |
| |
| std::string::const_iterator iter = expr.begin(); |
| std::string::const_iterator end = expr.end(); |
| bool r = phrase_parse(iter, end, calc, space); |
| |
| if (r && iter == end) |
| { |
| std::cout << "-------------------------\n"; |
| std::cout << "Parsing succeeded\n"; |
| std::cout << "-------------------------\n"; |
| return true; |
| } |
| else |
| { |
| std::cout << "-------------------------\n"; |
| std::cout << "Parsing failed\n"; |
| std::cout << "-------------------------\n"; |
| return false; |
| } |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // Main program |
| /////////////////////////////////////////////////////////////////////////////// |
| struct var_printer |
| { |
| var_printer(std::vector<int> const& stack) |
| : stack(stack) |
| { |
| } |
| |
| template <typename String, typename Data> |
| void operator()(String const& s, Data const& data) |
| { |
| std::cout << " " << s << ": " << stack[data] << std::endl; |
| } |
| |
| std::vector<int> const& stack; |
| }; |
| |
| int |
| main() |
| { |
| std::cout << "/////////////////////////////////////////////////////////\n\n"; |
| std::cout << "Expression parser...\n\n"; |
| std::cout << "/////////////////////////////////////////////////////////\n\n"; |
| std::cout << "Type some statements... "; |
| std::cout << "Then type period ('.') to compile, run and print results\n\n"; |
| |
| typedef std::string::const_iterator iterator_type; |
| typedef statement<iterator_type> statement; |
| |
| vmachine mach; // Our virtual machine |
| std::vector<int> code; // Our VM code |
| statement calc(code); // Our grammar |
| |
| std::string str; |
| std::string program; |
| while (std::getline(std::cin, str)) |
| { |
| if (str.empty() || str[0] == '.') |
| break; |
| program += str; |
| } |
| |
| if (::compile(calc, program)) |
| { |
| mach.execute(code, calc.nvars); |
| |
| std::cout << "Results------------------\n\n"; |
| calc.vars.for_each(var_printer(mach.get_stack())); |
| std::cout << "-------------------------\n\n"; |
| } |
| |
| std::cout << "Bye... :-) \n\n"; |
| return 0; |
| } |
| |
| |