kakoune/src/ranges.hh

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#ifndef ranges_hh_INCLUDED
#define ranges_hh_INCLUDED
#include <algorithm>
#include <utility>
#include <iterator>
#include <numeric>
namespace Kakoune
{
template<typename Func> struct ViewFactory { Func func; };
template<typename Func>
ViewFactory<std::decay_t<Func>>
make_view_factory(Func&& func) { return {std::forward<Func>(func)}; }
template<typename Range, typename Func>
decltype(auto) operator| (Range&& range, ViewFactory<Func> factory)
{
return factory.func(std::forward<Range>(range));
}
template<typename Range>
struct decay_range_impl { using type = std::decay_t<Range>; };
template<typename Range>
struct decay_range_impl<Range&> { using type = Range&; };
template<typename Range>
using decay_range = typename decay_range_impl<Range>::type;
template<typename Range>
struct ReverseView
{
decltype(auto) begin() { return m_range.rbegin(); }
decltype(auto) end() { return m_range.rend(); }
Range m_range;
};
inline auto reverse()
{
return make_view_factory([](auto&& range) {
using Range = decltype(range);
return ReverseView<decay_range<Range>>{std::forward<Range>(range)};
});
}
template<typename Range>
using IteratorOf = decltype(std::begin(std::declval<Range>()));
template<typename Range>
using ValueOf = typename Range::value_type;
template<typename Range, typename Filter>
struct FilterView
{
using RangeIt = IteratorOf<Range>;
struct Iterator : std::iterator<std::forward_iterator_tag,
typename std::iterator_traits<RangeIt>::value_type>
{
Iterator(const FilterView& view, RangeIt it, RangeIt end)
: m_it{std::move(it)}, m_end{std::move(end)}, m_view{view}
{
do_filter();
}
decltype(auto) operator*() { return *m_it; }
Iterator& operator++() { ++m_it; do_filter(); return *this; }
Iterator operator++(int) { auto copy = *this; ++(*this); return copy; }
friend bool operator==(const Iterator& lhs, const Iterator& rhs)
{
return lhs.m_it == rhs.m_it;
}
friend bool operator!=(const Iterator& lhs, const Iterator& rhs)
{
return not (lhs == rhs);
}
const RangeIt& base() const { return m_it; }
private:
void do_filter()
{
while (m_it != m_end and not m_view.m_filter(*m_it))
++m_it;
}
RangeIt m_it;
RangeIt m_end;
const FilterView& m_view;
};
Iterator begin() const { return {*this, std::begin(m_range), std::end(m_range)}; }
Iterator end() const { return {*this, std::end(m_range), std::end(m_range)}; }
Range m_range;
mutable Filter m_filter;
};
template<typename Filter>
inline auto filter(Filter f)
{
return make_view_factory([f = std::move(f)](auto&& range) {
using Range = decltype(range);
return FilterView<decay_range<Range>, Filter>{std::forward<Range>(range), std::move(f)};
});
}
template<typename Range, typename Transform>
struct TransformView
{
using RangeIt = IteratorOf<Range>;
using ResType = decltype(std::declval<Transform>()(*std::declval<RangeIt>()));
struct Iterator : std::iterator<std::forward_iterator_tag, std::remove_reference_t<ResType>>
{
Iterator(const TransformView& view, RangeIt it)
: m_it{std::move(it)}, m_view{view} {}
decltype(auto) operator*() { return m_view.m_transform(*m_it); }
Iterator& operator++() { ++m_it; return *this; }
Iterator operator++(int) { auto copy = *this; ++m_it; return copy; }
friend bool operator==(const Iterator& lhs, const Iterator& rhs)
{
return lhs.m_it == rhs.m_it;
}
friend bool operator!=(const Iterator& lhs, const Iterator& rhs)
{
return not (lhs == rhs);
}
RangeIt base() const { return m_it; }
private:
RangeIt m_it;
const TransformView& m_view;
};
Iterator begin() const { return {*this, std::begin(m_range)}; }
Iterator end() const { return {*this, std::end(m_range)}; }
Range m_range;
mutable Transform m_transform;
};
template<typename Transform>
inline auto transform(Transform t)
{
return make_view_factory([t = std::move(t)](auto&& range) {
using Range = decltype(range);
return TransformView<decay_range<Range>, Transform>{std::forward<Range>(range), std::move(t)};
});
}
template<typename Range, typename Separator = ValueOf<Range>,
typename ValueTypeParam = void>
struct SplitView
{
using RangeIt = IteratorOf<Range>;
using ValueType = std::conditional_t<std::is_same<void, ValueTypeParam>::value,
std::pair<IteratorOf<Range>, IteratorOf<Range>>,
ValueTypeParam>;
struct Iterator : std::iterator<std::forward_iterator_tag, ValueType>
{
Iterator(RangeIt pos, RangeIt end, char separator)
: pos(pos), sep(pos), end(end), separator(separator)
{
while (sep != end and *sep != separator)
++sep;
}
Iterator& operator++() { advance(); return *this; }
Iterator operator++(int) { auto copy = *this; advance(); return copy; }
bool operator==(const Iterator& other) const { return pos == other.pos; }
bool operator!=(const Iterator& other) const { return pos != other.pos; }
ValueType operator*() { return {pos, sep}; }
private:
void advance()
{
if (sep == end)
{
pos = end;
return;
}
pos = sep+1;
for (sep = pos; sep != end; ++sep)
{
if (*sep == separator)
break;
}
}
RangeIt pos;
RangeIt sep;
RangeIt end;
Separator separator;
};
Iterator begin() const { return {std::begin(m_range), std::end(m_range), m_separator}; }
Iterator end() const { return {std::end(m_range), std::end(m_range), m_separator}; }
Range m_range;
Separator m_separator;
};
template<typename ValueType = void, typename Separator>
auto split(Separator separator)
{
return make_view_factory([s = std::move(separator)](auto&& range) {
using Range = decltype(range);
return SplitView<decay_range<Range>, Separator, ValueType>{std::forward<Range>(range), std::move(s)};
});
}
template<typename Range1, typename Range2>
struct ConcatView
{
using RangeIt1 = decltype(begin(std::declval<Range1>()));
using RangeIt2 = decltype(begin(std::declval<Range2>()));
using ValueType = typename std::common_type_t<typename std::iterator_traits<RangeIt1>::value_type,
typename std::iterator_traits<RangeIt2>::value_type>;
struct Iterator : std::iterator<std::forward_iterator_tag, ValueType>
{
static_assert(std::is_convertible<typename std::iterator_traits<RangeIt1>::value_type, ValueType>::value, "");
static_assert(std::is_convertible<typename std::iterator_traits<RangeIt2>::value_type, ValueType>::value, "");
Iterator(RangeIt1 it1, RangeIt1 end1, RangeIt2 it2)
: m_it1(std::move(it1)), m_end1(std::move(end1)),
m_it2(std::move(it2)) {}
ValueType operator*() { return is2() ? *m_it2 : *m_it1; }
Iterator& operator++() { if (is2()) ++m_it2; else ++m_it1; return *this; }
Iterator operator++(int) { auto copy = *this; ++*this; return copy; }
friend bool operator==(const Iterator& lhs, const Iterator& rhs)
{
return lhs.m_it1 == rhs.m_it1 and lhs.m_end1 == rhs.m_end1 and
lhs.m_it2 == rhs.m_it2;
}
friend bool operator!=(const Iterator& lhs, const Iterator& rhs)
{
return not (lhs == rhs);
}
private:
bool is2() const { return m_it1 == m_end1; }
RangeIt1 m_it1;
RangeIt1 m_end1;
RangeIt2 m_it2;
};
ConcatView(Range1& range1, Range2& range2)
: m_range1(range1), m_range2(range2) {}
Iterator begin() const { return {m_range1.begin(), m_range1.end(), m_range2.begin()}; }
Iterator end() const { return {m_range1.end(), m_range1.end(), m_range2.end()}; }
private:
Range1& m_range1;
Range2& m_range2;
};
template<typename Range1, typename Range2>
ConcatView<Range1, Range2> concatenated(Range1&& range1, Range2&& range2)
{
return {range1, range2};
}
template<typename Range, typename T>
auto find(Range&& range, const T& value)
{
using std::begin; using std::end;
return std::find(begin(range), end(range), value);
}
template<typename Range, typename T>
auto find_if(Range&& range, T op)
{
using std::begin; using std::end;
return std::find_if(begin(range), end(range), op);
}
template<typename Range, typename T>
bool contains(Range&& range, const T& value)
{
using std::end;
return find(range, value) != end(range);
}
template<typename Range, typename T>
bool contains_that(Range&& range, T op)
{
using std::end;
return find_if(range, op) != end(range);
}
template<typename Range, typename U>
void unordered_erase(Range&& vec, U&& value)
{
auto it = find(vec, std::forward<U>(value));
if (it != vec.end())
{
using std::swap;
swap(vec.back(), *it);
vec.pop_back();
}
}
template<typename Range, typename Init, typename BinOp>
Init accumulate(Range&& c, Init&& init, BinOp&& op)
{
using std::begin; using std::end;
return std::accumulate(begin(c), end(c), init, op);
}
template<typename Container>
auto gather()
{
return make_view_factory([](auto&& range) {
using std::begin; using std::end;
return Container(begin(range), end(range));
});
}
}
#endif // ranges_hh_INCLUDED