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// Boost string_algo library join.hpp header file ---------------------------//
// Copyright Pavol Droba 2002-2006.
//
// 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)
// See http://www.boost.org/ for updates, documentation, and revision history.
#ifndef BOOST_STRING_JOIN_HPP
#define BOOST_STRING_JOIN_HPP
#include <boost/algorithm/string/config.hpp>
#include <boost/algorithm/string/detail/sequence.hpp>
#include <boost/range/value_type.hpp>
#include <boost/range/as_literal.hpp>
/*! \file
Defines join algorithm.
Join algorithm is a counterpart to split algorithms.
It joins strings from a 'list' by adding user defined separator.
Additionally there is a version that allows simple filtering
by providing a predicate.
*/
namespace boost {
namespace algorithm {
// join --------------------------------------------------------------//
//! Join algorithm
/*!
This algorithm joins all strings in a 'list' into one long string.
Segments are concatenated by given separator.
\param Input A container that holds the input strings. It must be a container-of-containers.
\param Separator A string that will separate the joined segments.
\return Concatenated string.
\note This function provides the strong exception-safety guarantee
*/
template< typename SequenceSequenceT, typename Range1T>
inline typename range_value<SequenceSequenceT>::type
join(
const SequenceSequenceT& Input,
const Range1T& Separator)
{
// Define working types
typedef typename range_value<SequenceSequenceT>::type ResultT;
typedef typename range_const_iterator<SequenceSequenceT>::type InputIteratorT;
// Parse input
InputIteratorT itBegin=::boost::begin(Input);
InputIteratorT itEnd=::boost::end(Input);
// Construct container to hold the result
ResultT Result;
// Append first element
if(itBegin!=itEnd)
{
detail::insert(Result, ::boost::end(Result), *itBegin);
++itBegin;
}
for(;itBegin!=itEnd; ++itBegin)
{
// Add separator
detail::insert(Result, ::boost::end(Result), ::boost::as_literal(Separator));
// Add element
detail::insert(Result, ::boost::end(Result), *itBegin);
}
return Result;
}
// join_if ----------------------------------------------------------//
//! Conditional join algorithm
/*!
This algorithm joins all strings in a 'list' into one long string.
Segments are concatenated by given separator. Only segments that
satisfy the predicate will be added to the result.
\param Input A container that holds the input strings. It must be a container-of-containers.
\param Separator A string that will separate the joined segments.
\param Pred A segment selection predicate
\return Concatenated string.
\note This function provides the strong exception-safety guarantee
*/
template< typename SequenceSequenceT, typename Range1T, typename PredicateT>
inline typename range_value<SequenceSequenceT>::type
join_if(
const SequenceSequenceT& Input,
const Range1T& Separator,
PredicateT Pred)
{
// Define working types
typedef typename range_value<SequenceSequenceT>::type ResultT;
typedef typename range_const_iterator<SequenceSequenceT>::type InputIteratorT;
// Parse input
InputIteratorT itBegin=::boost::begin(Input);
InputIteratorT itEnd=::boost::end(Input);
// Construct container to hold the result
ResultT Result;
// Roll to the first element that will be added
while(itBegin!=itEnd && !Pred(*itBegin)) ++itBegin;
// Add this element
if(itBegin!=itEnd)
{
detail::insert(Result, ::boost::end(Result), *itBegin);
++itBegin;
}
for(;itBegin!=itEnd; ++itBegin)
{
if(Pred(*itBegin))
{
// Add separator
detail::insert(Result, ::boost::end(Result), ::boost::as_literal(Separator));
// Add element
detail::insert(Result, ::boost::end(Result), *itBegin);
}
}
return Result;
}
} // namespace algorithm
// pull names to the boost namespace
using algorithm::join;
using algorithm::join_if;
} // namespace boost
#endif // BOOST_STRING_JOIN_HPP
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