2018-07-08 16:26:25 +03:00

345 lines
9.1 KiB
C++

// Formatting library for C++ - the core API
//
// Copyright (c) 2012 - present, Victor Zverovich
// All rights reserved.
//
// For the license information refer to format.h.
//
// Copyright (c) 2018 - present, Remotion (Igor Schulz)
// All Rights Reserved
// {fmt} support for ranges, containers and types tuple interface.
#ifndef FMT_RANGES_H_
#define FMT_RANGES_H_
#include "format.h"
#include <type_traits>
// output only up to N items from the range.
#ifndef FMT_RANGE_OUTPUT_LENGTH_LIMIT
#define FMT_RANGE_OUTPUT_LENGTH_LIMIT 256
#endif
FMT_BEGIN_NAMESPACE
template<typename Char>
struct formatting_base
{
template<typename ParseContext>
FMT_CONSTEXPR auto parse(ParseContext &ctx) -> decltype(ctx.begin())
{
return ctx.begin();
}
};
template<typename Char, typename Enable = void>
struct formatting_range : formatting_base<Char>
{
static FMT_CONSTEXPR_DECL const std::size_t range_length_limit =
FMT_RANGE_OUTPUT_LENGTH_LIMIT; // output only up to N items from the range.
Char prefix;
Char delimiter;
Char postfix;
formatting_range()
: prefix('{')
, delimiter(',')
, postfix('}')
{
}
static FMT_CONSTEXPR_DECL const bool add_delimiter_spaces = true;
static FMT_CONSTEXPR_DECL const bool add_prepostfix_space = false;
};
template<typename Char, typename Enable = void>
struct formatting_tuple : formatting_base<Char>
{
Char prefix;
Char delimiter;
Char postfix;
formatting_tuple()
: prefix('(')
, delimiter(',')
, postfix(')')
{
}
static FMT_CONSTEXPR_DECL const bool add_delimiter_spaces = true;
static FMT_CONSTEXPR_DECL const bool add_prepostfix_space = false;
};
namespace internal {
template<typename RangeT, typename OutputIterator>
void copy(const RangeT &range, OutputIterator out)
{
for (auto it = range.begin(), end = range.end(); it != end; ++it)
*out++ = *it;
}
template<typename OutputIterator>
void copy(const char *str, OutputIterator out)
{
const char *p_curr = str;
while (*p_curr)
{
*out++ = *p_curr++;
}
}
template<typename OutputIterator>
void copy(char ch, OutputIterator out)
{
*out++ = ch;
}
/// Return true value if T has std::string interface, like std::string_view.
template<typename T>
class is_like_std_string
{
template<typename U>
static auto check(U *p) -> decltype(p->find('a'), p->length(), p->data(), int());
template<typename>
static void check(...);
public:
static FMT_CONSTEXPR_DECL const bool value = !std::is_void<decltype(check<T>(FMT_NULL))>::value;
};
template<typename... Ts>
struct conditional_helper
{
};
template<typename T, typename _ = void>
struct is_range_ : std::false_type
{
};
#if !FMT_MSC_VER || FMT_MSC_VER > 1800
template<typename T>
struct is_range_<T, typename std::conditional<false,
conditional_helper<decltype(internal::declval<T>().begin()), decltype(internal::declval<T>().end())>, void>::type>
: std::true_type
{
};
#endif
/// tuple_size and tuple_element check.
template<typename T>
class is_tuple_like_
{
template<typename U>
static auto check(U *p) -> decltype(std::tuple_size<U>::value, internal::declval<typename std::tuple_element<0, U>::type>(), int());
template<typename>
static void check(...);
public:
static FMT_CONSTEXPR_DECL const bool value = !std::is_void<decltype(check<T>(FMT_NULL))>::value;
};
// Check for integer_sequence
#if defined(__cpp_lib_integer_sequence) || FMT_MSC_VER >= 1900
template<typename T, T... N>
using integer_sequence = std::integer_sequence<T, N...>;
template<std::size_t... N>
using index_sequence = std::index_sequence<N...>;
template<std::size_t N>
using make_index_sequence = std::make_index_sequence<N>;
#else
template<typename T, T... N>
struct integer_sequence
{
typedef T value_type;
static FMT_CONSTEXPR std::size_t size()
{
return sizeof...(N);
}
};
template<std::size_t... N>
using index_sequence = integer_sequence<std::size_t, N...>;
template<typename T, std::size_t N, T... Ns>
struct make_integer_sequence : make_integer_sequence<T, N - 1, N - 1, Ns...>
{
};
template<typename T, T... Ns>
struct make_integer_sequence<T, 0, Ns...> : integer_sequence<T, Ns...>
{
};
template<std::size_t N>
using make_index_sequence = make_integer_sequence<std::size_t, N>;
#endif
template<class Tuple, class F, size_t... Is>
void for_each(index_sequence<Is...>, Tuple &&tup, F &&f) FMT_NOEXCEPT
{
using std::get;
// using free function get<I>(T) now.
const int _[] = {0, ((void)f(get<Is>(tup)), 0)...};
(void)_; // blocks warnings
}
template<class T>
FMT_CONSTEXPR make_index_sequence<std::tuple_size<T>::value> get_indexes(T const &)
{
return {};
}
template<class Tuple, class F>
void for_each(Tuple &&tup, F &&f)
{
const auto indexes = get_indexes(tup);
for_each(indexes, std::forward<Tuple>(tup), std::forward<F>(f));
}
template<typename Arg>
FMT_CONSTEXPR const char *format_str_quoted(
bool add_space, const Arg &, typename std::enable_if<!is_like_std_string<typename std::decay<Arg>::type>::value>::type * = nullptr)
{
return add_space ? " {}" : "{}";
}
template<typename Arg>
FMT_CONSTEXPR const char *format_str_quoted(
bool add_space, const Arg &, typename std::enable_if<is_like_std_string<typename std::decay<Arg>::type>::value>::type * = nullptr)
{
return add_space ? " \"{}\"" : "\"{}\"";
}
FMT_CONSTEXPR const char *format_str_quoted(bool add_space, const char *)
{
return add_space ? " \"{}\"" : "\"{}\"";
}
FMT_CONSTEXPR const wchar_t *format_str_quoted(bool add_space, const wchar_t *)
{
return add_space ? L" \"{}\"" : L"\"{}\"";
}
FMT_CONSTEXPR const char *format_str_quoted(bool add_space, const char)
{
return add_space ? " '{}'" : "'{}'";
}
FMT_CONSTEXPR const wchar_t *format_str_quoted(bool add_space, const wchar_t)
{
return add_space ? L" '{}'" : L"'{}'";
}
} // namespace internal
template<typename T>
struct is_tuple_like
{
static FMT_CONSTEXPR_DECL const bool value = internal::is_tuple_like_<T>::value && !internal::is_range_<T>::value;
};
template<typename TupleT, typename Char>
struct formatter<TupleT, Char, typename std::enable_if<fmt::is_tuple_like<TupleT>::value>::type>
{
private:
// C++11 generic lambda for format()
template<typename FormatContext>
struct format_each
{
template<typename T>
void operator()(const T &v)
{
if (i > 0)
{
if (formatting.add_prepostfix_space)
{
*out++ = ' ';
}
internal::copy(formatting.delimiter, out);
}
format_to(out, internal::format_str_quoted((formatting.add_delimiter_spaces && i > 0), v), v);
++i;
}
formatting_tuple<Char> &formatting;
std::size_t &i;
typename std::add_lvalue_reference<decltype(std::declval<FormatContext>().out())>::type out;
};
public:
formatting_tuple<Char> formatting;
template<typename ParseContext>
FMT_CONSTEXPR auto parse(ParseContext &ctx) -> decltype(ctx.begin())
{
return formatting.parse(ctx);
}
template<typename FormatContext = format_context>
auto format(const TupleT &values, FormatContext &ctx) -> decltype(ctx.out())
{
auto out = ctx.out();
std::size_t i = 0;
internal::copy(formatting.prefix, out);
internal::for_each(values, format_each<FormatContext>{formatting, i, out});
if (formatting.add_prepostfix_space)
{
*out++ = ' ';
}
internal::copy(formatting.postfix, out);
return ctx.out();
}
};
template<typename T>
struct is_range
{
static FMT_CONSTEXPR_DECL const bool value = internal::is_range_<T>::value && !internal::is_like_std_string<T>::value;
};
template<typename RangeT, typename Char>
struct formatter<RangeT, Char, typename std::enable_if<fmt::is_range<RangeT>::value>::type>
{
formatting_range<Char> formatting;
template<typename ParseContext>
FMT_CONSTEXPR auto parse(ParseContext &ctx) -> decltype(ctx.begin())
{
return formatting.parse(ctx);
}
template<typename FormatContext>
typename FormatContext::iterator format(const RangeT &values, FormatContext &ctx)
{
auto out = ctx.out();
internal::copy(formatting.prefix, out);
std::size_t i = 0;
for (auto it = values.begin(), end = values.end(); it != end; ++it)
{
if (i > 0)
{
if (formatting.add_prepostfix_space)
{
*out++ = ' ';
}
internal::copy(formatting.delimiter, out);
}
format_to(out, internal::format_str_quoted((formatting.add_delimiter_spaces && i > 0), *it), *it);
if (++i > formatting.range_length_limit)
{
format_to(out, " ... <other elements>");
break;
}
}
if (formatting.add_prepostfix_space)
{
*out++ = ' ';
}
internal::copy(formatting.postfix, out);
return ctx.out();
}
};
FMT_END_NAMESPACE
#endif // FMT_RANGES_H_