| // -*- C++ -*- |
| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef _LIBCPP___FORMAT_RANGE_FORMATTER_H |
| #define _LIBCPP___FORMAT_RANGE_FORMATTER_H |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| #include <__algorithm/ranges_copy.h> |
| #include <__availability> |
| #include <__chrono/statically_widen.h> |
| #include <__concepts/same_as.h> |
| #include <__config> |
| #include <__format/buffer.h> |
| #include <__format/concepts.h> |
| #include <__format/format_args.h> |
| #include <__format/format_context.h> |
| #include <__format/format_error.h> |
| #include <__format/formatter.h> |
| #include <__format/formatter_output.h> |
| #include <__format/parser_std_format_spec.h> |
| #include <__iterator/back_insert_iterator.h> |
| #include <__ranges/concepts.h> |
| #include <__ranges/data.h> |
| #include <__ranges/size.h> |
| #include <__type_traits/remove_cvref.h> |
| #include <string_view> |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| #if _LIBCPP_STD_VER >= 23 |
| |
| template <class _Tp, class _CharT = char> |
| requires same_as<remove_cvref_t<_Tp>, _Tp> && formattable<_Tp, _CharT> |
| struct _LIBCPP_TEMPLATE_VIS range_formatter { |
| _LIBCPP_HIDE_FROM_ABI constexpr void set_separator(basic_string_view<_CharT> __separator) noexcept { |
| __separator_ = __separator; |
| } |
| _LIBCPP_HIDE_FROM_ABI constexpr void |
| set_brackets(basic_string_view<_CharT> __opening_bracket, basic_string_view<_CharT> __closing_bracket) noexcept { |
| __opening_bracket_ = __opening_bracket; |
| __closing_bracket_ = __closing_bracket; |
| } |
| |
| _LIBCPP_HIDE_FROM_ABI constexpr formatter<_Tp, _CharT>& underlying() noexcept { return __underlying_; } |
| _LIBCPP_HIDE_FROM_ABI constexpr const formatter<_Tp, _CharT>& underlying() const noexcept { return __underlying_; } |
| |
| template <class _ParseContext> |
| _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __parse_ctx) { |
| auto __begin = __parser_.__parse(__parse_ctx, __format_spec::__fields_range); |
| auto __end = __parse_ctx.end(); |
| // Note the cases where __begin == __end in this code only happens when the |
| // replacement-field has no terminating }, or when the parse is manually |
| // called with a format-spec. The former is an error and the latter means |
| // using a formatter without the format functions or print. |
| if (__begin == __end) [[unlikely]] |
| return __parse_empty_range_underlying_spec(__parse_ctx, __begin); |
| |
| // The n field overrides a possible m type, therefore delay applying the |
| // effect of n until the type has been procesed. |
| bool __clear_brackets = (*__begin == _CharT('n')); |
| if (__clear_brackets) { |
| ++__begin; |
| if (__begin == __end) [[unlikely]] { |
| // Since there is no more data, clear the brackets before returning. |
| set_brackets({}, {}); |
| return __parse_empty_range_underlying_spec(__parse_ctx, __begin); |
| } |
| } |
| |
| __parse_type(__begin, __end); |
| if (__clear_brackets) |
| set_brackets({}, {}); |
| if (__begin == __end) [[unlikely]] |
| return __parse_empty_range_underlying_spec(__parse_ctx, __begin); |
| |
| bool __has_range_underlying_spec = *__begin == _CharT(':'); |
| if (__has_range_underlying_spec) { |
| // range-underlying-spec: |
| // : format-spec |
| ++__begin; |
| } else if (__begin != __end && *__begin != _CharT('}')) |
| // When there is no underlaying range the current parse should have |
| // consumed the format-spec. If not, the not consumed input will be |
| // processed by the underlying. For example {:-} for a range in invalid, |
| // the sign field is not present. Without this check the underlying_ will |
| // get -} as input which my be valid. |
| std::__throw_format_error("The format-spec should consume the input or end with a '}'"); |
| |
| __parse_ctx.advance_to(__begin); |
| __begin = __underlying_.parse(__parse_ctx); |
| |
| // This test should not be required if __has_range_underlying_spec is false. |
| // However this test makes sure the underlying formatter left the parser in |
| // a valid state. (Note this is not a full protection against evil parsers. |
| // For example |
| // } this is test for the next argument {} |
| // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^ |
| // could consume more than it should. |
| if (__begin != __end && *__begin != _CharT('}')) |
| std::__throw_format_error("The format-spec should consume the input or end with a '}'"); |
| |
| if (__parser_.__type_ != __format_spec::__type::__default) { |
| // [format.range.formatter]/6 |
| // If the range-type is s or ?s, then there shall be no n option and no |
| // range-underlying-spec. |
| if (__clear_brackets) { |
| if (__parser_.__type_ == __format_spec::__type::__string) |
| std::__throw_format_error("The n option and type s can't be used together"); |
| std::__throw_format_error("The n option and type ?s can't be used together"); |
| } |
| if (__has_range_underlying_spec) { |
| if (__parser_.__type_ == __format_spec::__type::__string) |
| std::__throw_format_error("Type s and an underlying format specification can't be used together"); |
| std::__throw_format_error("Type ?s and an underlying format specification can't be used together"); |
| } |
| } else if (!__has_range_underlying_spec) |
| std::__set_debug_format(__underlying_); |
| |
| return __begin; |
| } |
| |
| template <ranges::input_range _Rp, class _FormatContext> |
| requires formattable<ranges::range_reference_t<_Rp>, _CharT> && |
| same_as<remove_cvref_t<ranges::range_reference_t<_Rp>>, _Tp> |
| _LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator format(_Rp&& __range, _FormatContext& __ctx) const { |
| __format_spec::__parsed_specifications<_CharT> __specs = __parser_.__get_parsed_std_specifications(__ctx); |
| |
| if (!__specs.__has_width()) |
| return __format_range(__range, __ctx, __specs); |
| |
| // The size of the buffer needed is: |
| // - open bracket characters |
| // - close bracket character |
| // - n elements where every element may have a different size |
| // - (n -1) separators |
| // The size of the element is hard to predict, knowing the type helps but |
| // it depends on the format-spec. As an initial estimate we guess 6 |
| // characters. |
| // Typically both brackets are 1 character and the separator is 2 |
| // characters. Which means there will be |
| // (n - 1) * 2 + 1 + 1 = n * 2 character |
| // So estimate 8 times the range size as buffer. |
| std::size_t __capacity_hint = 0; |
| if constexpr (std::ranges::sized_range<_Rp>) |
| __capacity_hint = 8 * ranges::size(__range); |
| __format::__retarget_buffer<_CharT> __buffer{__capacity_hint}; |
| basic_format_context<typename __format::__retarget_buffer<_CharT>::__iterator, _CharT> __c{ |
| __buffer.__make_output_iterator(), __ctx}; |
| |
| __format_range(__range, __c, __specs); |
| |
| return __formatter::__write_string_no_precision(__buffer.__view(), __ctx.out(), __specs); |
| } |
| |
| template <ranges::input_range _Rp, class _FormatContext> |
| typename _FormatContext::iterator _LIBCPP_HIDE_FROM_ABI |
| __format_range(_Rp&& __range, _FormatContext& __ctx, __format_spec::__parsed_specifications<_CharT> __specs) const { |
| if constexpr (same_as<_Tp, _CharT>) { |
| switch (__specs.__std_.__type_) { |
| case __format_spec::__type::__string: |
| case __format_spec::__type::__debug: |
| return __format_as_string(__range, __ctx, __specs.__std_.__type_ == __format_spec::__type::__debug); |
| default: |
| return __format_as_sequence(__range, __ctx); |
| } |
| } else |
| return __format_as_sequence(__range, __ctx); |
| } |
| |
| template <ranges::input_range _Rp, class _FormatContext> |
| _LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator |
| __format_as_string(_Rp&& __range, _FormatContext& __ctx, bool __debug_format) const { |
| // When the range is contiguous use a basic_string_view instead to avoid a |
| // copy of the underlying data. The basic_string_view formatter |
| // specialization is the "basic" string formatter in libc++. |
| if constexpr (ranges::contiguous_range<_Rp> && std::ranges::sized_range<_Rp>) { |
| std::formatter<basic_string_view<_CharT>, _CharT> __formatter; |
| if (__debug_format) |
| __formatter.set_debug_format(); |
| return __formatter.format( |
| basic_string_view<_CharT>{ |
| ranges::data(__range), |
| ranges::size(__range), |
| }, |
| __ctx); |
| } else { |
| std::formatter<basic_string<_CharT>, _CharT> __formatter; |
| if (__debug_format) |
| __formatter.set_debug_format(); |
| // P2106's from_range has not been implemented yet. Instead use a simple |
| // copy operation. |
| // TODO FMT use basic_string's "from_range" constructor. |
| // return std::formatter<basic_string<_CharT>, _CharT>{}.format(basic_string<_CharT>{from_range, __range}, __ctx); |
| basic_string<_CharT> __str; |
| ranges::copy(__range, back_insert_iterator{__str}); |
| return __formatter.format(__str, __ctx); |
| } |
| } |
| |
| template <ranges::input_range _Rp, class _FormatContext> |
| _LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator |
| __format_as_sequence(_Rp&& __range, _FormatContext& __ctx) const { |
| __ctx.advance_to(ranges::copy(__opening_bracket_, __ctx.out()).out); |
| bool __use_separator = false; |
| for (auto&& __e : __range) { |
| if (__use_separator) |
| __ctx.advance_to(ranges::copy(__separator_, __ctx.out()).out); |
| else |
| __use_separator = true; |
| |
| __ctx.advance_to(__underlying_.format(__e, __ctx)); |
| } |
| |
| return ranges::copy(__closing_bracket_, __ctx.out()).out; |
| } |
| |
| __format_spec::__parser<_CharT> __parser_{.__alignment_ = __format_spec::__alignment::__left}; |
| |
| private: |
| template <contiguous_iterator _Iterator> |
| _LIBCPP_HIDE_FROM_ABI constexpr void __parse_type(_Iterator& __begin, _Iterator __end) { |
| switch (*__begin) { |
| case _CharT('m'): |
| if constexpr (__fmt_pair_like<_Tp>) { |
| set_brackets(_LIBCPP_STATICALLY_WIDEN(_CharT, "{"), _LIBCPP_STATICALLY_WIDEN(_CharT, "}")); |
| set_separator(_LIBCPP_STATICALLY_WIDEN(_CharT, ", ")); |
| ++__begin; |
| } else |
| std::__throw_format_error("The range-format-spec type m requires two elements for a pair or tuple"); |
| break; |
| |
| case _CharT('s'): |
| if constexpr (same_as<_Tp, _CharT>) { |
| __parser_.__type_ = __format_spec::__type::__string; |
| ++__begin; |
| } else |
| std::__throw_format_error("The range-format-spec type s requires formatting a character type"); |
| break; |
| |
| case _CharT('?'): |
| ++__begin; |
| if (__begin == __end || *__begin != _CharT('s')) |
| std::__throw_format_error("The format-spec should consume the input or end with a '}'"); |
| if constexpr (same_as<_Tp, _CharT>) { |
| __parser_.__type_ = __format_spec::__type::__debug; |
| ++__begin; |
| } else |
| std::__throw_format_error("The range-format-spec type ?s requires formatting a character type"); |
| } |
| } |
| |
| template <class _ParseContext> |
| _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator |
| __parse_empty_range_underlying_spec(_ParseContext& __parse_ctx, typename _ParseContext::iterator __begin) { |
| __parse_ctx.advance_to(__begin); |
| [[maybe_unused]] typename _ParseContext::iterator __result = __underlying_.parse(__parse_ctx); |
| _LIBCPP_ASSERT(__result == __begin, |
| "the underlying's parse function should not advance the input beyond the end of the input"); |
| return __begin; |
| } |
| |
| formatter<_Tp, _CharT> __underlying_; |
| basic_string_view<_CharT> __separator_ = _LIBCPP_STATICALLY_WIDEN(_CharT, ", "); |
| basic_string_view<_CharT> __opening_bracket_ = _LIBCPP_STATICALLY_WIDEN(_CharT, "["); |
| basic_string_view<_CharT> __closing_bracket_ = _LIBCPP_STATICALLY_WIDEN(_CharT, "]"); |
| }; |
| |
| #endif //_LIBCPP_STD_VER >= 23 |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP___FORMAT_RANGE_FORMATTER_H |