| 1 | /*============================================================================= |
| 2 | Copyright (c) 2001-2010 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 | #include <boost/spirit/include/qi.hpp> |
| 8 | #include <boost/lambda/lambda.hpp> |
| 9 | #include <boost/bind/bind.hpp> |
| 10 | |
| 11 | #include <iostream> |
| 12 | |
| 13 | // Presented are various ways to attach semantic actions |
| 14 | // * Using plain function pointer |
| 15 | // * Using simple function object |
| 16 | // * Using boost.bind with a plain function |
| 17 | // * Using boost.bind with a member function |
| 18 | // * Using boost.lambda |
| 19 | |
| 20 | //[tutorial_semantic_action_functions |
| 21 | namespace client |
| 22 | { |
| 23 | namespace qi = boost::spirit::qi; |
| 24 | |
| 25 | // A plain function |
| 26 | void print(int const& i) |
| 27 | { |
| 28 | std::cout << i << std::endl; |
| 29 | } |
| 30 | |
| 31 | // A member function |
| 32 | struct writer |
| 33 | { |
| 34 | void print(int const& i) const |
| 35 | { |
| 36 | std::cout << i << std::endl; |
| 37 | } |
| 38 | }; |
| 39 | |
| 40 | // A function object |
| 41 | struct print_action |
| 42 | { |
| 43 | void operator()(int const& i, qi::unused_type, qi::unused_type) const |
| 44 | { |
| 45 | std::cout << i << std::endl; |
| 46 | } |
| 47 | }; |
| 48 | } |
| 49 | //] |
| 50 | |
| 51 | int main() |
| 52 | { |
| 53 | using boost::spirit::qi::int_; |
| 54 | using boost::spirit::qi::parse; |
| 55 | using client::print; |
| 56 | using client::writer; |
| 57 | using client::print_action; |
| 58 | |
| 59 | { // example using plain function |
| 60 | |
| 61 | char const *first = "{42}" , *last = first + std::strlen(s: first); |
| 62 | //[tutorial_attach_actions1 |
| 63 | parse(first, last, expr: '{' >> int_[&print] >> '}'); |
| 64 | //] |
| 65 | } |
| 66 | |
| 67 | { // example using simple function object |
| 68 | |
| 69 | char const *first = "{43}" , *last = first + std::strlen(s: first); |
| 70 | //[tutorial_attach_actions2 |
| 71 | parse(first, last, expr: '{' >> int_[print_action()] >> '}'); |
| 72 | //] |
| 73 | } |
| 74 | |
| 75 | { // example using boost.bind with a plain function |
| 76 | |
| 77 | char const *first = "{44}" , *last = first + std::strlen(s: first); |
| 78 | using boost::placeholders::_1; |
| 79 | //[tutorial_attach_actions3 |
| 80 | parse(first, last, expr: '{' >> int_[boost::bind(f: &print, a1: _1)] >> '}'); |
| 81 | //] |
| 82 | } |
| 83 | |
| 84 | { // example using boost.bind with a member function |
| 85 | |
| 86 | char const *first = "{44}" , *last = first + std::strlen(s: first); |
| 87 | using boost::placeholders::_1; |
| 88 | //[tutorial_attach_actions4 |
| 89 | writer w; |
| 90 | parse(first, last, expr: '{' >> int_[boost::bind(f: &writer::print, a1: &w, a2: _1)] >> '}'); |
| 91 | //] |
| 92 | } |
| 93 | |
| 94 | { // example using boost.lambda |
| 95 | |
| 96 | namespace lambda = boost::lambda; |
| 97 | char const *first = "{45}" , *last = first + std::strlen(s: first); |
| 98 | using lambda::_1; |
| 99 | //[tutorial_attach_actions5 |
| 100 | parse(first, last, expr: '{' >> int_[std::cout << _1 << '\n'] >> '}'); |
| 101 | //] |
| 102 | } |
| 103 | |
| 104 | return 0; |
| 105 | } |
| 106 | |
| 107 | |
| 108 | |
| 109 | |
| 110 | |