Subject: [Boost-commit] svn:boost r57726 - trunk/libs/spirit/example/karma
From: hartmut.kaiser_at_[hidden]
Date: 2009-11-17 11:45:52
Author: hkaiser
Date: 2009-11-17 11:45:52 EST (Tue, 17 Nov 2009)
New Revision: 57726
URL: http://svn.boost.org/trac/boost/changeset/57726
Log:
Spirit: updated karma example
Text files modified:
trunk/libs/spirit/example/karma/key_value_sequence.cpp | 56 ++++++++++++++++++++-------------------
1 files changed, 29 insertions(+), 27 deletions(-)
Modified: trunk/libs/spirit/example/karma/key_value_sequence.cpp
==============================================================================
--- trunk/libs/spirit/example/karma/key_value_sequence.cpp (original)
+++ trunk/libs/spirit/example/karma/key_value_sequence.cpp 2009-11-17 11:45:52 EST (Tue, 17 Nov 2009)
@@ -3,8 +3,10 @@
// 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)
-// The main purpose of this example is to show how a single container type can
-// be formatted using different output grammars.
+// The main purpose of this example is to show how we can generate output from
+// a container holding key/value pairs.
+//
+// For more information see here: http://spirit.sourceforge.net/home/?p=282
#include <boost/config/warning_disable.hpp>
#include <boost/spirit/include/karma.hpp>
@@ -20,42 +22,42 @@
namespace client
{
namespace karma = boost::spirit::karma;
- namespace phoenix = boost::phoenix;
+
+ typedef std::pair<std::string, boost::optional<std::string> > pair_type;
template <typename OutputIterator>
- bool key_value_sequence(OutputIterator sink
- , std::map<std::string, std::string> const& m)
+ struct keys_and_values
+ : karma::grammar<OutputIterator, std::vector<pair_type>()>
{
- using karma::eps;
- using karma::omit;
- using karma::_val;
- using karma::string;
-
- karma::rule<OutputIterator, std::pair<std::string const, std::string>()> param;
-
- param = eps(!phoenix::empty(phoenix::at_c<1>(_val)))
- << string << "=" << string
- | string << omit[string]
- ;
-
- return karma::generate(sink, param % '&', m);
- }
+ keys_and_values()
+ : keys_and_values::base_type(query)
+ {
+ query = pair << *('&' << pair);
+ pair = karma::string << -('=' << karma::string);
+ }
+
+ karma::rule<OutputIterator, std::vector<pair_type>()> query;
+ karma::rule<OutputIterator, pair_type()> pair;
+ };
}
///////////////////////////////////////////////////////////////////////////////
int main()
{
- typedef std::map<std::string, std::string>::value_type value_type;
+ namespace karma = boost::spirit::karma;
+
+ typedef std::vector<client::pair_type>::value_type value_type;
+ typedef std::back_insert_iterator<std::string> sink_type;
- std::map<std::string, std::string> m;
- m.insert(value_type("key1", "value1"));
- m.insert(value_type("key2", ""));
- m.insert(value_type("key3", "value3"));
- m.insert(value_type("key4", ""));
+ std::vector<client::pair_type> v;
+ v.push_back(value_type("key1", boost::optional<std::string>("value1")));
+ v.push_back(value_type("key2", boost::optional<std::string>()));
+ v.push_back(value_type("key3", boost::optional<std::string>("")));
std::string generated;
- std::back_insert_iterator<std::string> sink(generated);
- if (!client::key_value_sequence(sink, m))
+ sink_type sink(generated);
+ client::keys_and_values<sink_type> g;
+ if (!karma::generate(sink, g, v))
{
std::cout << "-------------------------\n";
std::cout << "Generating failed\n";