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swift-mirror/stdlib/public/stubs/Unicode/UnicodeWord.cpp

52 lines
1.7 KiB
C++

//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2022 - 2023 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
#if SWIFT_STDLIB_ENABLE_UNICODE_DATA
#include "Common/WordData.h"
#else
#include "swift/Runtime/Debug.h"
#endif
#include "swift/shims/UnicodeData.h"
#include <stdint.h>
SWIFT_RUNTIME_STDLIB_INTERNAL
__swift_uint8_t _swift_stdlib_getWordBreakProperty(__swift_uint32_t scalar) {
#if !SWIFT_STDLIB_ENABLE_UNICODE_DATA
swift::swift_abortDisabledUnicodeSupport();
#else
auto index = 1; //0th element is a dummy element
while (index < WORD_BREAK_DATA_COUNT) {
auto entry = _swift_stdlib_words[index];
// Shift the range count out of the value.
auto lower = (entry << 11) >> 11;
// Shift the enum out first, then shift out the scalar value.
auto upper = lower + (entry >> 21) - 1;
//If we want the left child of the current node in our virtual tree,
//that's at index * 2, if we want the right child it's at (index * 2) + 1
if (scalar < lower) {
index = 2 * index;
} else if (scalar <= upper) {
return _swift_stdlib_words_data[index];
} else {
index = 2 * index + 1;
}
}
// If we made it out here, then our scalar was not found in the word
// array (this occurs when a scalar doesn't map to any word break
// property). Return the max value here to indicate .any.
return UINT8_MAX;
#endif
}