home/src/utf8_iterator.hh

133 lines
3.2 KiB
C++

#ifndef utf8_iterator_hh_INCLUDED
#define utf8_iterator_hh_INCLUDED
#include "utf8.hh"
#include <iterator>
namespace Kakoune
{
namespace utf8
{
// adapter for an iterator on bytes which permits to iterate
// on unicode codepoints instead.
template<typename Iterator,
typename InvalidPolicy = utf8::InvalidPolicy::Pass>
class iterator : public std::iterator<std::bidirectional_iterator_tag,
Codepoint, CharCount>
{
public:
iterator() = default;
iterator(Iterator it, Iterator begin, Iterator end)
: m_it{std::move(it)}, m_begin{std::move(begin)}, m_end{std::move(end)}
{}
template<typename Container>
iterator(Iterator it, const Container& c)
: m_it{std::move(it)}, m_begin{std::begin(c)}, m_end{std::end(c)}
{}
iterator& operator++()
{
m_it = utf8::next(m_it, m_end);
invalidate_value();
return *this;
}
iterator operator++(int)
{
iterator save = *this;
++*this;
return save;
}
iterator& operator--()
{
m_it = utf8::previous(m_it, m_begin);
invalidate_value();
return *this;
}
iterator operator--(int)
{
iterator save = *this;
--*this;
return save;
}
iterator operator+(CharCount count) const
{
if (count < 0)
return operator-(-count);
iterator res = *this;
while (count--)
++res;
return res;
}
iterator operator-(CharCount count) const
{
if (count < 0)
return operator+(-count);
iterator res = *this;
while (count--)
--res;
return res;
}
bool operator==(const iterator& other) const { return m_it == other.m_it; }
bool operator!=(const iterator& other) const { return m_it != other.m_it; }
bool operator< (const iterator& other) const { return m_it < other.m_it; }
bool operator<= (const iterator& other) const { return m_it <= other.m_it; }
bool operator> (const iterator& other) const { return m_it > other.m_it; }
bool operator>= (const iterator& other) const { return m_it >= other.m_it; }
bool operator==(const Iterator& other) { return m_it == other; }
bool operator!=(const Iterator& other) { return m_it != other; }
bool operator< (const Iterator& other) const { return m_it < other; }
bool operator<= (const Iterator& other) const { return m_it <= other; }
bool operator> (const Iterator& other) const { return m_it > other; }
bool operator>= (const Iterator& other) const { return m_it >= other; }
CharCount operator-(const iterator& other) const
{
return utf8::distance(other.m_it, m_it);
}
Codepoint operator*() const
{
return get_value();
}
const Iterator& base() const { return m_it; }
Iterator& base() { return m_it; }
private:
void invalidate_value() { m_value = -1; }
Codepoint get_value() const
{
if (m_value == -1)
m_value = utf8::codepoint<InvalidPolicy>(m_it, m_end);
return m_value;
}
Iterator m_it;
Iterator m_begin;
Iterator m_end;
mutable Codepoint m_value = -1;
};
}
}
#endif // utf8_iterator_hh_INCLUDED