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// 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_GETLINE_H
#define SCN_SCAN_GETLINE_H
#include "common.h"
namespace scn {
SCN_BEGIN_NAMESPACE
namespace detail {
template <typename WrappedRange,
typename String,
typename Until,
typename CharT = typename WrappedRange::char_type>
error getline_impl(WrappedRange& r, String& str, Until until)
{
auto pred = until_pred<CharT>{until};
auto s = read_until_space_zero_copy(r, pred, true);
if (!s) {
return s.error();
}
if (s.value().size() != 0) {
auto size = s.value().size();
if (pred(s.value().last(1))) {
--size;
}
str.clear();
str.resize(size);
std::copy(s.value().begin(), s.value().begin() + size,
str.begin());
return {};
}
String tmp;
auto out = std::back_inserter(tmp);
auto e = read_until_space(r, out, pred, true);
if (!e) {
return e;
}
if (pred(span<const CharT>(&*(tmp.end() - 1), 1))) {
tmp.pop_back();
}
str = SCN_MOVE(tmp);
return {};
}
template <typename WrappedRange,
typename Until,
typename CharT = typename WrappedRange::char_type>
error getline_impl(WrappedRange& r,
basic_string_view<CharT>& str,
Until until)
{
static_assert(
WrappedRange::is_contiguous,
"Cannot getline a string_view from a non-contiguous range");
auto pred = until_pred<CharT>{until};
auto s = read_until_space_zero_copy(r, pred, true);
if (!s) {
return s.error();
}
SCN_ASSERT(s.value().size(), "");
auto size = s.value().size();
if (pred(s.value().last(1))) {
--size;
}
str = basic_string_view<CharT>{s.value().data(), size};
return {};
}
#if SCN_HAS_STRING_VIEW
template <typename WrappedRange,
typename Until,
typename CharT = typename WrappedRange::char_type>
auto getline_impl(WrappedRange& r,
std::basic_string_view<CharT>& str,
Until until) -> error
{
auto sv = ::scn::basic_string_view<CharT>{};
auto ret = getline_impl(r, sv, until);
str = ::std::basic_string_view<CharT>{sv.data(), sv.size()};
return ret;
}
#endif
} // namespace detail
/**
* Read the range in \c r into \c str until \c until is found.
* \c until will be skipped in parsing: it will not be pushed into \c
* str, and the returned range will go past it.
*
* If `str` is convertible to a `basic_string_view`:
* - And if `r` is a `contiguous_range`:
* - `str` is set to point inside `r` with the appropriate length
* - if not, returns an error
*
* Otherwise, clears `str` by calling `str.clear()`, and then reads the
* range into `str` as if by repeatedly calling \c str.push_back.
* `str.reserve()` is also required to be present.
*
* `Until` can either be the same as `r` character type (`char` or
* `wchar_t`), or `code_point`.
*
* \code{.cpp}
* auto source = "hello\nworld"
* std::string line;
* auto result = scn::getline(source, line, '\n');
* // line == "hello"
* // result.range() == "world"
*
* // Using the other overload
* result = scn::getline(result.range(), line);
* // line == "world"
* // result.empty() == true
* \endcode
*/
#if SCN_DOXYGEN
template <typename Range, typename String, typename Until>
auto getline(Range&& r, String& str, Until until)
-> detail::scan_result_for_range<Range>;
#else
template <typename Range, typename String, typename Until>
SCN_NODISCARD auto getline(Range&& r, String& str, Until until)
-> detail::scan_result_for_range<Range>
{
auto wrapped = wrap(SCN_FWD(r));
auto err = getline_impl(wrapped, str, 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
/**
* Equivalent to \ref getline with the last parameter set to
* <tt>'\\n'</tt> with the appropriate character type.
*
* In other words, reads `r` into `str` until <tt>'\\n'</tt> is found.
*
* The character type is determined by `r`.
*/
#if SCN_DOXYGEN
template <typename Range,
typename String,
typename CharT = typename detail::extract_char_type<
ranges::iterator_t<range_wrapper_for_t<Range>>>::type>
auto getline(Range&& r, String& str)
-> detail::scan_result_for_range<Range>;
#else
template <typename Range,
typename String,
typename CharT = typename detail::extract_char_type<
ranges::iterator_t<range_wrapper_for_t<Range>>>::type>
SCN_NODISCARD auto getline(Range&& r, String& str)
-> detail::scan_result_for_range<Range>
{
return getline(SCN_FWD(r), str, detail::ascii_widen<CharT>('\n'));
}
#endif
SCN_END_NAMESPACE
} // namespace scn
#endif
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