forked from boostorg/regex
John Maddock
c05af49444
Added first start to Unicode support. Enabled external template instance support. Fixed VC6 support. [SVN r25914]
262 lines
7.9 KiB
C++
262 lines
7.9 KiB
C++
/*
|
|
*
|
|
* Copyright (c) 2004
|
|
* Dr John Maddock
|
|
*
|
|
* Use, modification and distribution are subject to 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)
|
|
*
|
|
*/
|
|
|
|
/*
|
|
* LOCATION: see http://www.boost.org for most recent version.
|
|
* FILE unicode_iterator.hpp
|
|
* VERSION see <boost/version.hpp>
|
|
* DESCRIPTION: Iterator adapters for converting between different Unicode encodings.
|
|
*/
|
|
|
|
#ifndef BOOST_REGEX_UNICODE_ITERATOR_HPP
|
|
#define BOOST_REGEX_UNICODE_ITERATOR_HPP
|
|
#include <boost/cstdint.hpp>
|
|
#include <boost/assert.hpp>
|
|
#include <boost/iterator/iterator_facade.hpp>
|
|
#include <boost/static_assert.hpp>
|
|
#include <stdexcept>
|
|
#ifndef BOOST_NO_STD_LOCALE
|
|
#include <sstream>
|
|
#endif
|
|
|
|
namespace boost{
|
|
|
|
namespace detail{
|
|
|
|
static const ::boost::uint16_t high_surrogate_base = 0xD7C0u;
|
|
static const ::boost::uint16_t low_surrogate_base = 0xDC00u;
|
|
static const ::boost::uint32_t ten_bit_mask = 0x3FFu;
|
|
|
|
inline bool is_high_surrogate(::boost::uint16_t v)
|
|
{
|
|
return (v & 0xFC00u) == 0xd800u;
|
|
}
|
|
inline bool is_low_surrogate(::boost::uint16_t v)
|
|
{
|
|
return (v & 0xFC00u) == 0xdc00u;
|
|
}
|
|
template <class T>
|
|
inline bool is_surrogate(T v)
|
|
{
|
|
return (v & 0xF800u) == 0xd800;
|
|
}
|
|
|
|
}
|
|
|
|
template <class BaseIterator, class U16Type = ::boost::uint16_t>
|
|
class u32_to_u16_iterator
|
|
: public boost::iterator_facade<u32_to_u16_iterator<BaseIterator, U16Type>, U16Type, std::bidirectional_iterator_tag, const U16Type>
|
|
{
|
|
typedef boost::iterator_facade<u32_to_u16_iterator<BaseIterator>, U16Type, std::bidirectional_iterator_tag, const U16Type> base_type;
|
|
typedef typename std::iterator_traits<BaseIterator>::value_type base_value_type;
|
|
|
|
BOOST_STATIC_ASSERT(sizeof(base_value_type)*CHAR_BIT == 32);
|
|
BOOST_STATIC_ASSERT(sizeof(U16Type)*CHAR_BIT == 16);
|
|
public:
|
|
typename base_type::reference
|
|
dereference()const
|
|
{
|
|
if(m_current == 2)
|
|
const_cast<u32_to_u16_iterator*>(this)->extract_current();
|
|
return m_values[m_current];
|
|
}
|
|
bool equal(const u32_to_u16_iterator& that)const
|
|
{
|
|
if(m_position == that.m_position)
|
|
{
|
|
if((m_current >= 2) && (that.m_current < 2))
|
|
const_cast<u32_to_u16_iterator*>(this)->extract_current();
|
|
else if((m_current < 2) && (that.m_current >= 2))
|
|
const_cast<u32_to_u16_iterator&>(that).extract_current();
|
|
if(m_current == that.m_current)
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
void increment()
|
|
{
|
|
// if we have a pending read then read now, so that we know whether
|
|
// to skip a position, or move to a low-surrogate:
|
|
if(m_current == 2)
|
|
{
|
|
// pending read:
|
|
extract_current();
|
|
}
|
|
// move to the next surrogate position:
|
|
++m_current;
|
|
// if we've reached the end skip a position:
|
|
if(m_values[m_current] == 0)
|
|
{
|
|
m_current = 2;
|
|
++m_position;
|
|
}
|
|
}
|
|
void decrement()
|
|
{
|
|
if(m_current != 1)
|
|
{
|
|
// decrementing an iterator always leads to a valid position:
|
|
--m_position;
|
|
extract_current();
|
|
m_current = m_values[1] ? 1 : 0;
|
|
}
|
|
else
|
|
{
|
|
m_current = 0;
|
|
}
|
|
}
|
|
BaseIterator base()const
|
|
{
|
|
return m_position;
|
|
}
|
|
// construct:
|
|
u32_to_u16_iterator() : m_position(), m_current(0)
|
|
{
|
|
m_values[2] = 0;
|
|
}
|
|
u32_to_u16_iterator(BaseIterator b) : m_position(b), m_current(2)
|
|
{
|
|
m_values[2] = 0;
|
|
}
|
|
private:
|
|
void invalid_code_point(::boost::uint32_t val)
|
|
{
|
|
#ifndef BOOST_NO_STD_LOCALE
|
|
std::stringstream ss;
|
|
ss << "Invalid UTF-32 code point U+" << std::showbase << std::hex << val << " encountered while trying to encode UTF-16 sequence";
|
|
std::out_of_range e(ss.str());
|
|
#else
|
|
std::out_of_range e("Invalid UTF-32 code point encountered while trying to encode UTF-16 sequence");
|
|
#endif
|
|
boost::throw_exception(e);
|
|
}
|
|
|
|
void extract_current()
|
|
{
|
|
// begin by checking for a code point out of range:
|
|
if(static_cast< ::boost::uint32_t>(*m_position) >= 0x10000u)
|
|
{
|
|
if(static_cast< ::boost::uint32_t>(*m_position) > 0x10FFFFu)
|
|
invalid_code_point(*m_position);
|
|
// split into two surrogates:
|
|
base_value_type v = *m_position;
|
|
m_values[0] = static_cast<U16Type>(v >> 10) + detail::high_surrogate_base;
|
|
m_values[1] = static_cast<U16Type>(v & detail::ten_bit_mask) + detail::low_surrogate_base;
|
|
m_current = 0;
|
|
BOOST_ASSERT(detail::is_high_surrogate(m_values[0]));
|
|
BOOST_ASSERT(detail::is_low_surrogate(m_values[1]));
|
|
}
|
|
else
|
|
{
|
|
// 16-bit code point:
|
|
m_values[0] = static_cast<U16Type>(*m_position);
|
|
m_values[1] = 0;
|
|
m_current = 0;
|
|
// value must not be a surrogate:
|
|
if(detail::is_surrogate(m_values[0]))
|
|
invalid_code_point(*m_position);
|
|
}
|
|
}
|
|
BaseIterator m_position;
|
|
U16Type m_values[3];
|
|
unsigned m_current;
|
|
};
|
|
|
|
template <class BaseIterator, class U32Type = ::boost::uint32_t>
|
|
class u16_to_u32_iterator
|
|
: public boost::iterator_facade<u16_to_u32_iterator<BaseIterator, U32Type>, U32Type, std::bidirectional_iterator_tag, const U32Type>
|
|
{
|
|
typedef boost::iterator_facade<u16_to_u32_iterator<BaseIterator>, U32Type, std::bidirectional_iterator_tag, const U32Type> base_type;
|
|
// special values for pending iterator reads:
|
|
BOOST_STATIC_CONSTANT(::boost::uint32_t, pending_read = 0xffffffffu);
|
|
|
|
typedef typename std::iterator_traits<BaseIterator>::value_type base_value_type;
|
|
|
|
BOOST_STATIC_ASSERT(sizeof(base_value_type)*CHAR_BIT == 16);
|
|
BOOST_STATIC_ASSERT(sizeof(U32Type)*CHAR_BIT == 32);
|
|
|
|
public:
|
|
typename base_type::reference
|
|
dereference()const
|
|
{
|
|
if(m_value == pending_read)
|
|
const_cast<u16_to_u32_iterator*>(this)->extract_current();
|
|
return m_value;
|
|
}
|
|
bool equal(const u16_to_u32_iterator& that)const
|
|
{
|
|
return m_position == that.m_position;
|
|
}
|
|
void increment()
|
|
{
|
|
// skip high surrogate first if there is one:
|
|
if(detail::is_high_surrogate(*m_position)) ++m_position;
|
|
++m_position;
|
|
m_value = pending_read;
|
|
}
|
|
void decrement()
|
|
{
|
|
--m_position;
|
|
// if we have a low surrogate then go back one more:
|
|
if(detail::is_low_surrogate(*m_position))
|
|
--m_position;
|
|
m_value = pending_read;
|
|
}
|
|
BaseIterator base()const
|
|
{
|
|
return m_position;
|
|
}
|
|
// construct:
|
|
u16_to_u32_iterator() : m_position()
|
|
{
|
|
}
|
|
u16_to_u32_iterator(BaseIterator b) : m_position(b)
|
|
{
|
|
m_value = pending_read;
|
|
}
|
|
private:
|
|
void invalid_code_point(::boost::uint16_t val)
|
|
{
|
|
#ifndef BOOST_NO_STD_LOCALE
|
|
std::stringstream ss;
|
|
ss << "Misplaced UTF-16 surrogate U+" << std::showbase << std::hex << val << " encountered while trying to encode UTF-32 sequence";
|
|
std::out_of_range e(ss.str());
|
|
#else
|
|
std::out_of_range e("Misplaced UTF-16 surrogate encountered while trying to encode UTF-32 sequence");
|
|
#endif
|
|
boost::throw_exception(e);
|
|
}
|
|
void extract_current()
|
|
{
|
|
m_value = static_cast<U32Type>(static_cast< ::boost::uint16_t>(*m_position));
|
|
// if the last value is a high surrogate then adjust m_position and m_value as needed:
|
|
if(detail::is_high_surrogate(*m_position))
|
|
{
|
|
// precondition; next value must have be a low-surrogate:
|
|
::boost::uint16_t t = *++m_position;
|
|
if((*m_position & 0xFC00u) != 0xDC00u)
|
|
invalid_code_point(t);
|
|
m_value = (m_value - detail::high_surrogate_base) << 10;
|
|
m_value |= (static_cast<U32Type>(static_cast< ::boost::uint16_t>(t)) & detail::ten_bit_mask);
|
|
--m_position;
|
|
}
|
|
// postcondition; result must not be a surrogate:
|
|
if(detail::is_surrogate(m_value))
|
|
invalid_code_point(static_cast< ::boost::uint16_t>(m_value));
|
|
}
|
|
BaseIterator m_position;
|
|
U32Type m_value;
|
|
};
|
|
|
|
}
|
|
|
|
#endif // BOOST_REGEX_UNICODE_ITERATOR_HPP
|