[Boost-commit] svn:boost r44529 - in trunk: boost/spirit/home/karma/action libs/spirit/example/karma libs/spirit/example/qi

From: hartmut.kaiser_at_[hidden]
Date: 2008-04-17 21:39:58

Author: hkaiser
Date: 2008-04-17 21:39:58 EDT (Thu, 17 Apr 2008)
New Revision: 44529
URL: http://svn.boost.org/trac/boost/changeset/44529

Log:
Spirit.Karma: added simple function support for semantic actions, added example.
Added:
   trunk/libs/spirit/example/karma/actions.cpp   (contents, props changed)
Text files modified: 
   trunk/boost/spirit/home/karma/action/action.hpp |     8 +++++---                                
   trunk/libs/spirit/example/qi/actions.cpp        |    16 +++++++++++++---                        
   2 files changed, 18 insertions(+), 6 deletions(-)

Modified: trunk/boost/spirit/home/karma/action/action.hpp
==============================================================================
--- trunk/boost/spirit/home/karma/action/action.hpp	(original)
+++ trunk/boost/spirit/home/karma/action/action.hpp	2008-04-17 21:39:58 EDT (Thu, 17 Apr 2008)
@@ -13,6 +13,7 @@
 #include <boost/spirit/home/support/component.hpp>
 #include <boost/spirit/home/support/detail/values.hpp>
 #include <boost/spirit/home/support/attribute_of.hpp>
+#include <boost/spirit/home/support/detail/action_dispatch.hpp>
 #include <boost/spirit/home/karma/domain.hpp>
 #include <boost/mpl/if.hpp>
 #include <boost/mpl/identity.hpp>
@@ -60,9 +61,10 @@
             // call the function, passing the parameter, the context
             // and a bool flag that the client can set to false to
             // fail parsing.
-            bool pass = true;
-            spirit::right(component)(
-                spirit::detail::pass_value<param_type>::call(p), ctx, pass);
+            // call the function, passing the attribute, the context.
+            // The client can return false to fail parsing.
+            bool pass = spirit::detail::action_dispatch(
+                spirit::right(component), p, ctx);
 
             return pass &&
                 director::generate(spirit::left(component), sink, ctx, d, p);

Added: trunk/libs/spirit/example/karma/actions.cpp
==============================================================================
--- (empty file)
+++ trunk/libs/spirit/example/karma/actions.cpp	2008-04-17 21:39:58 EDT (Thu, 17 Apr 2008)
@@ -0,0 +1,114 @@
+/*=============================================================================
+    Copyright (c) 2001-2008 Hartmut Kaiser
+    Copyright (c) 2001-2008 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)
+=============================================================================*/
+
+#include <iostream>
+#include <strstream>
+
+#include <boost/spirit/include/karma.hpp>
+#include <boost/lambda/lambda.hpp>
+#include <boost/bind.hpp>
+#include <boost/function_output_iterator.hpp>
+
+// Presented are various ways to attach semantic actions
+//  * Using plain function pointers
+//  * Using plain simple function objects
+//  * Using plain boost.bind
+//  * Using plain boost.lambda
+
+using namespace boost::spirit;
+
+void read(int& i)
+{
+    i = 42;
+}
+
+struct read_action
+{
+    void operator()(int& i, unused_type, unused_type) const
+    {
+        i = 42;
+    }
+};
+
+///////////////////////////////////////////////////////////////////////////
+template <typename String>
+struct string_appender 
+{
+    string_appender(String& s) 
+    :   str(s) 
+    {}
+    
+    template <typename T>
+    void operator()(T const &x) const 
+    {
+        str += x;
+    }
+
+    String& str;
+};
+
+template <typename String>
+inline string_appender<String> 
+make_string_appender(String& str)
+{
+    return string_appender<String>(str);
+}
+
+
+///////////////////////////////////////////////////////////////////////////////
+int main()
+{
+    using boost::make_function_output_iterator;
+
+    { // example using plain functions
+        std::string generated;
+        bool result = karma::generate(
+            make_function_output_iterator(make_string_appender(generated)), 
+            '{' << int_[&read] << '}');
+
+        if (result)
+            std::cout << "Simple function: " << generated << std::endl;
+    }
+
+    { // example using simple function objects
+        std::string generated;
+        bool result = karma::generate(
+            make_function_output_iterator(make_string_appender(generated)), 
+            '{' << int_[read_action()] << '}');
+
+        if (result)
+            std::cout << "Simple function object: " << generated << std::endl;
+    }
+
+    { // example using boost.bind
+        std::string generated;
+        bool result = karma::generate(
+            make_function_output_iterator(make_string_appender(generated)), 
+            '{' << int_[boost::bind(&read, _1)] << '}');
+
+        if (result)
+            std::cout << "Boost.Bind: " << generated << std::endl;
+    }
+
+    { // example using boost.lambda
+        using boost::lambda::_1;
+
+        std::string generated;
+        std::stringstream strm("42");
+        
+        bool result = karma::generate(
+            make_function_output_iterator(make_string_appender(generated)), 
+            '{' << int_[strm >> _1] << '}');
+
+        if (result)
+            std::cout << "Boost.Lambda: " << generated << std::endl;
+    }
+    
+    return 0;
+}
+

Modified: trunk/libs/spirit/example/qi/actions.cpp
==============================================================================
--- trunk/libs/spirit/example/qi/actions.cpp	(original)
+++ trunk/libs/spirit/example/qi/actions.cpp	2008-04-17 21:39:58 EDT (Thu, 17 Apr 2008)
@@ -1,3 +1,10 @@
+/*=============================================================================
+    Copyright (c) 2001-2008 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)
+=============================================================================*/
+
 #include <iostream>
 #include <boost/spirit/include/qi.hpp>
 #include <boost/lambda/lambda.hpp>
@@ -11,14 +18,14 @@
 
 using namespace boost::spirit;
 
-void write(int& i)
+void write(int const& i)
 {
     std::cout << i << std::endl;
 }
 
 struct write_action
 {
-    void operator()(int& i, unused_type, unused_type) const
+    void operator()(int const& i, unused_type, unused_type) const
     {
         std::cout << i << std::endl;
     }
@@ -47,5 +54,8 @@
 
         using boost::lambda::_1;
         qi::parse(s1, e1, '{' >> int_[std::cout << _1 << '\n'] >> '}');
-    }}
+    }
+    
+    return 0;
+}