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/*
* Copyright (C) 2018 The Android Open Source Project
*
* 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
*
* http://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.
*/
#include "annotator/strip-unpaired-brackets.h"
#include <iterator>
#include "utils/base/logging.h"
#include "utils/utf8/unicodetext.h"
namespace libtextclassifier3 {
CodepointSpan StripUnpairedBrackets(
const UnicodeText::const_iterator& span_begin,
const UnicodeText::const_iterator& span_end, CodepointSpan span,
const UniLib& unilib) {
if (span_begin == span_end || !span.IsValid() || span.IsEmpty()) {
return span;
}
UnicodeText::const_iterator begin = span_begin;
const UnicodeText::const_iterator end = span_end;
const char32 begin_char = *begin;
const char32 paired_begin_char = unilib.GetPairedBracket(begin_char);
if (paired_begin_char != begin_char) {
if (!unilib.IsOpeningBracket(begin_char) ||
std::find(begin, end, paired_begin_char) == end) {
++begin;
++span.first;
}
}
if (span.first == span.second) {
return span;
}
const char32 end_char = *std::prev(end);
const char32 paired_end_char = unilib.GetPairedBracket(end_char);
if (paired_end_char != end_char) {
if (!unilib.IsClosingBracket(end_char) ||
std::find(begin, end, paired_end_char) == end) {
--span.second;
}
}
// Should not happen, but let's make sure.
if (span.first > span.second) {
TC3_LOG(WARNING) << "Inverse indices result: " << span.first << ", "
<< span.second;
span.second = span.first;
}
return span;
}
CodepointSpan StripUnpairedBrackets(const UnicodeText& context,
CodepointSpan span, const UniLib& unilib) {
if (!span.IsValid() || span.IsEmpty()) {
return span;
}
const UnicodeText span_text = UnicodeText::Substring(
context, span.first, span.second, /*do_copy=*/false);
return StripUnpairedBrackets(span_text.begin(), span_text.end(), span,
unilib);
}
CodepointSpan StripUnpairedBrackets(const std::string& context,
CodepointSpan span, const UniLib& unilib) {
return StripUnpairedBrackets(UTF8ToUnicodeText(context, /*do_copy=*/false),
span, unilib);
}
} // namespace libtextclassifier3