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Diffstat (limited to 'src/third-party/scnlib/include/scn/scan/ignore.h')
| -rw-r--r-- | src/third-party/scnlib/include/scn/scan/ignore.h | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/src/third-party/scnlib/include/scn/scan/ignore.h b/src/third-party/scnlib/include/scn/scan/ignore.h new file mode 100644 index 0000000..415a877 --- /dev/null +++ b/src/third-party/scnlib/include/scn/scan/ignore.h @@ -0,0 +1,189 @@ +// Copyright 2017 Elias Kosunen +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// https://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. +// +// This file is a part of scnlib: +// https://github.com/eliaskosunen/scnlib + +#ifndef SCN_SCAN_IGNORE_H +#define SCN_SCAN_IGNORE_H + +#include "common.h" + +namespace scn { + SCN_BEGIN_NAMESPACE + + namespace detail { + template <typename CharT> + struct ignore_iterator { + using value_type = CharT; + using pointer = value_type*; + using reference = value_type&; + using difference_type = std::ptrdiff_t; + using iterator_category = std::output_iterator_tag; + + constexpr ignore_iterator() = default; + + SCN_CONSTEXPR14 ignore_iterator& operator=(CharT) noexcept + { + return *this; + } + constexpr const ignore_iterator& operator=(CharT) const noexcept + { + return *this; + } + + SCN_CONSTEXPR14 ignore_iterator& operator*() noexcept + { + return *this; + } + constexpr const ignore_iterator& operator*() const noexcept + { + return *this; + } + + SCN_CONSTEXPR14 ignore_iterator& operator++() noexcept + { + return *this; + } + constexpr const ignore_iterator& operator++() const noexcept + { + return *this; + } + }; + + template <typename CharT> + struct ignore_iterator_n { + using value_type = CharT; + using pointer = value_type*; + using reference = value_type&; + using difference_type = std::ptrdiff_t; + using iterator_category = std::output_iterator_tag; + + ignore_iterator_n() = default; + ignore_iterator_n(difference_type n) : i(n) {} + + constexpr const ignore_iterator_n& operator=(CharT) const noexcept + { + return *this; + } + + constexpr const ignore_iterator_n& operator*() const noexcept + { + return *this; + } + + SCN_CONSTEXPR14 ignore_iterator_n& operator++() noexcept + { + ++i; + return *this; + } + + constexpr bool operator==(const ignore_iterator_n& o) const noexcept + { + return i == o.i; + } + constexpr bool operator!=(const ignore_iterator_n& o) const noexcept + { + return !(*this == o); + } + + difference_type i{0}; + }; + + template <typename WrappedRange, + typename Until, + typename CharT = typename WrappedRange::char_type> + error ignore_until_impl(WrappedRange& r, Until until) + { + ignore_iterator<CharT> it{}; + return read_until_space(r, it, until_pred<CharT>{until}, false); + } + + template <typename WrappedRange, + typename Until, + typename CharT = typename WrappedRange::char_type> + error ignore_until_n_impl(WrappedRange& r, + ranges::range_difference_t<WrappedRange> n, + Until until) + { + ignore_iterator_n<CharT> begin{}, end{n}; + return read_until_space_ranged(r, begin, end, + until_pred<CharT>{until}, false); + } + } // namespace detail + + /** + * Advances the beginning of \c r until \c until is found. + */ +#if SCN_DOXYGEN + template <typename Range, typename Until> + auto ignore_until(Range&& r, Until until) + -> detail::scan_result_for_range<Range>; +#else + template <typename Range, typename Until> + SCN_NODISCARD auto ignore_until(Range&& r, Until until) + -> detail::scan_result_for_range<Range> + { + auto wrapped = wrap(SCN_FWD(r)); + auto err = detail::ignore_until_impl(wrapped, until); + if (!err) { + auto e = wrapped.reset_to_rollback_point(); + if (!e) { + err = e; + } + } + else { + wrapped.set_rollback_point(); + } + return detail::wrap_result( + wrapped_error{err}, detail::range_tag<Range>{}, SCN_MOVE(wrapped)); + } +#endif + + /** + * Advances the beginning of \c r until \c until is found, or the + * beginning has been advanced \c n times. + * + * `Until` can be the `r` character type (`char` or `wchar_t`), or + * `code_point`. + */ +#if SCN_DOXYGEN + template <typename Range, typename Until> + auto ignore_until_n(Range&& r, + ranges::range_difference_t<Range> n, + Until until) -> detail::scan_result_for_range<Range>; +#else + template <typename Range, typename Until> + SCN_NODISCARD auto ignore_until_n(Range&& r, + ranges::range_difference_t<Range> n, + Until until) + -> detail::scan_result_for_range<Range> + { + auto wrapped = wrap(SCN_FWD(r)); + auto err = detail::ignore_until_n_impl(wrapped, n, until); + if (!err) { + auto e = wrapped.reset_to_rollback_point(); + if (!e) { + err = e; + } + } + return detail::wrap_result( + wrapped_error{err}, detail::range_tag<Range>{}, SCN_MOVE(wrapped)); + } +#endif + + SCN_END_NAMESPACE +} // namespace scn + +#endif |