1/*
2 * Copyright (c) 2021-2022 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16#include "ustring.h"
17
18#include <iterator>
19
20namespace panda::es2panda::util {
21
22std::string StringView::Mutf8() const noexcept
23{
24    std::string mutf8;
25    mutf8.reserve(sv_.size());
26
27    Iterator iter(*this);
28
29    while (iter.HasNext()) {
30        Mutf8Encode(&mutf8, iter.Next());
31    }
32
33    return mutf8;
34}
35
36char32_t StringView::DecodeSurrogates(char32_t high, char32_t low)
37{
38    constexpr auto OFFSET = 10;
39    char32_t result = (high - Constants::SURROGATE_HIGH_MIN) << OFFSET;
40    result += low - Constants::SURROGATE_LOW_MAX;
41    result += Constants::CELESTIAL_OFFSET;
42    return result;
43}
44
45std::tuple<char32_t, char32_t> StringView::EncodeSurrogate(char32_t cp)
46{
47    constexpr auto OFFSET = 10;
48    char32_t cu1 = ((cp - Constants::CELESTIAL_OFFSET) >> OFFSET) | Constants::SURROGATE_HIGH_MIN;
49    char32_t cu2 = (cp & Constants::SURROGATE_LOW_MARKER) | Constants::SURROGATE_HIGH_MAX;
50
51    return {cu1, cu2};
52}
53
54void StringView::Iterator::SkipCp() const
55{
56    if (!HasNext()) {
57        return;
58    }
59
60    char32_t cu0 = static_cast<uint8_t>(*iter_++);
61
62    if (cu0 < Constants::UTF8_1BYTE_LIMIT) {
63        return;
64    }
65
66    if ((cu0 & Constants::UTF8_3BYTE_HEADER) == Constants::UTF8_2BYTE_HEADER) {
67        iter_ += 1U;
68        return;
69    }
70
71    if ((cu0 & Constants::UTF8_4BYTE_HEADER) == Constants::UTF8_3BYTE_HEADER) {
72        iter_ += 2U;
73        return;
74    }
75
76    if (((cu0 & Constants::UTF8_DECODE_4BYTE_MASK) == Constants::UTF8_4BYTE_HEADER) &&
77        (cu0 <= Constants::UTF8_DECODE_4BYTE_LIMIT)) {
78        iter_ += 3U;
79        return;
80    }
81}
82
83}  // namespace panda::es2panda::util
84
85// NOLINTNEXTLINE(cert-dcl58-cpp)
86namespace std {
87
88ostream &operator<<(ostream &os, const panda::es2panda::util::StringView &us)
89{
90    os << us.Utf8();
91    return os;
92}
93
94}  // namespace std
95