gtsam/wrap/spirit_actors.h

124 lines
2.9 KiB
C++

/**
* @file spirit_actors.h
*
* @brief Additional actors for the wrap parser
*
* @date Dec 8, 2011
* @author Alex Cunningham
*/
#pragma once
#include <boost/spirit/include/classic_core.hpp>
#include <boost/spirit/include/classic_ref_actor.hpp>
namespace boost {
namespace spirit {
BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN
///////////////////////////////////////////////////////////////////////////
// Summary:
// A semantic action policy that calls pop_back method.
// (This doc uses convention available in actors.hpp)
// Note that this action performs a "safe" pop, that checks the size
// before popping to avoid segfaults
//
// Actions (what it does):
// ref.pop_back();
//
// Policy name:
// pop_action
//
// Policy holder, corresponding helper method:
// ref_actor, clear_a( ref );
//
// () operators: both.
//
// See also ref_actor for more details.
///////////////////////////////////////////////////////////////////////////
struct pop_action
{
template< typename T>
void act(T& ref_) const
{
if (!ref_.empty())
ref_.pop_back();
}
};
///////////////////////////////////////////////////////////////////////////
// helper method that creates a and_assign_actor.
///////////////////////////////////////////////////////////////////////////
template<typename T>
inline ref_actor<T,pop_action> pop_a(T& ref_)
{
return ref_actor<T,pop_action>(ref_);
}
///////////////////////////////////////////////////////////////////////////
// Summary:
//
// A semantic action policy that appends a set of values to the back of a
// container.
// (This doc uses convention available in actors.hpp)
//
// Actions (what it does and what ref, value_ref must support):
// ref.push_back( values );
// ref.push_back( T::value_type(first,last) );
// ref.push_back( value_ref );
//
// Policy name:
// append_action
//
// Policy holder, corresponding helper method:
// ref_value_actor, append_a( ref );
// ref_const_ref_actor, append_a( ref, value_ref );
//
// () operators: both
//
// See also ref_value_actor and ref_const_ref_actor for more details.
///////////////////////////////////////////////////////////////////////////
struct append_action
{
template< typename T, typename ValueT >
void act(T& ref_, ValueT const& value_) const
{
ref_.insert(ref_.begin(), value_.begin(), value_.end());
}
template<typename T,typename IteratorT>
void act(
T& ref_,
IteratorT const& first_,
IteratorT const& last_
) const
{
ref_.insert(ref_.end(), first_, last_);
}
};
template<typename T>
inline ref_value_actor<T,append_action>
append_a(T& ref_)
{
return ref_value_actor<T,append_action>(ref_);
}
template<typename T,typename ValueT>
inline ref_const_ref_actor<T,ValueT,append_action>
append_a(
T& ref_,
ValueT const& value_
)
{
return ref_const_ref_actor<T,ValueT,append_action>(ref_,value_);
}
BOOST_SPIRIT_CLASSIC_NAMESPACE_END
}
}