| 1 | // Copyright (c) 2001-2010 Hartmut Kaiser |
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| 2 | // |
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| 3 | // Distributed under the Boost Software License, Version 1.0. (See accompanying |
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| 4 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
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| 5 | |
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| 6 | // The main purpose of this example is to show how we can generate output from |
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| 7 | // a container holding key/value pairs. |
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| 8 | // |
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| 9 | // For more information see here: http://spirit.sourceforge.net/home/?p=400 |
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| 10 | |
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| 11 | #include <boost/spirit/include/karma.hpp> |
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| 12 | #include <boost/spirit/include/karma_stream.hpp> |
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| 13 | #include <boost/phoenix.hpp> |
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| 14 | #include <boost/fusion/include/std_pair.hpp> |
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| 15 | |
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| 16 | #include <iostream> |
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| 17 | #include <map> |
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| 18 | #include <algorithm> |
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| 19 | #include <cstdlib> |
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| 20 | |
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| 21 | namespace client |
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| 22 | { |
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| 23 | namespace karma = boost::spirit::karma; |
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| 24 | |
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| 25 | typedef std::pair<std::string, boost::optional<std::string> > pair_type; |
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| 26 | |
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| 27 | template <typename OutputIterator> |
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| 28 | struct keys_and_values |
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| 29 | : karma::grammar<OutputIterator, std::vector<pair_type>()> |
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| 30 | { |
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| 31 | keys_and_values() |
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| 32 | : keys_and_values::base_type(query) |
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| 33 | { |
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| 34 | query = pair << *('&' << pair); |
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| 35 | pair = karma::string << -('=' << karma::string); |
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| 36 | } |
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| 37 | |
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| 38 | karma::rule<OutputIterator, std::vector<pair_type>()> query; |
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| 39 | karma::rule<OutputIterator, pair_type()> pair; |
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| 40 | }; |
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| 41 | } |
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| 42 | |
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| 43 | /////////////////////////////////////////////////////////////////////////////// |
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| 44 | int main() |
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| 45 | { |
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| 46 | namespace karma = boost::spirit::karma; |
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| 47 | |
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| 48 | typedef std::vector<client::pair_type>::value_type value_type; |
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| 49 | typedef std::back_insert_iterator<std::string> sink_type; |
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| 50 | |
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| 51 | std::vector<client::pair_type> v; |
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| 52 | v.push_back(x: value_type("key1" , boost::optional<std::string>("value1" ))); |
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| 53 | v.push_back(x: value_type("key2" , boost::optional<std::string>())); |
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| 54 | v.push_back(x: value_type("key3" , boost::optional<std::string>("" ))); |
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| 55 | |
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| 56 | std::string generated; |
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| 57 | sink_type sink(generated); |
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| 58 | client::keys_and_values<sink_type> g; |
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| 59 | if (!karma::generate(sink_&: sink, expr: g, attr: v)) |
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| 60 | { |
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| 61 | std::cout << "-------------------------\n" ; |
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| 62 | std::cout << "Generating failed\n" ; |
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| 63 | std::cout << "-------------------------\n" ; |
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| 64 | } |
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| 65 | else |
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| 66 | { |
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| 67 | std::cout << "-------------------------\n" ; |
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| 68 | std::cout << "Generated: " << generated << "\n" ; |
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| 69 | std::cout << "-------------------------\n" ; |
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| 70 | } |
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| 71 | return 0; |
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| 72 | } |
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| 73 | |
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| 74 | |
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