LatinIME/native/jni/src/char_utils.h

78 lines
2.2 KiB
C++

/*
* Copyright (C) 2010 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.
*/
#ifndef LATINIME_CHAR_UTILS_H
#define LATINIME_CHAR_UTILS_H
#include <cctype>
#include <stdint.h>
namespace latinime {
inline static bool isAsciiUpper(unsigned short c) {
// Note: isupper(...) reports false positives for some Cyrillic characters, causing them to
// be incorrectly lower-cased using toAsciiLower(...) rather than latin_tolower(...).
return (c >= 'A' && c <= 'Z');
}
inline static unsigned short toAsciiLower(unsigned short c) {
return c - 'A' + 'a';
}
inline static bool isAscii(unsigned short c) {
return isascii(static_cast<int>(c)) != 0;
}
unsigned short latin_tolower(const unsigned short c);
/**
* Table mapping most combined Latin, Greek, and Cyrillic characters
* to their base characters. If c is in range, BASE_CHARS[c] == c
* if c is not a combined character, or the base character if it
* is combined.
*/
static const int BASE_CHARS_SIZE = 0x0500;
extern const uint16_t BASE_CHARS[BASE_CHARS_SIZE];
inline static unsigned short toBaseChar(unsigned short c) {
if (c < BASE_CHARS_SIZE) {
return BASE_CHARS[c];
}
return c;
}
inline static unsigned short toLowerCase(const unsigned short c) {
if (isAsciiUpper(c)) {
return toAsciiLower(c);
} else if (isAscii(c)) {
return c;
}
return latin_tolower(c);
}
inline static unsigned short toBaseLowerCase(const unsigned short c) {
return toLowerCase(toBaseChar(c));
}
inline static bool isSkippableChar(const uint16_t character) {
// TODO: Do not hardcode here
return character == '\'' || character == '-';
}
} // namespace latinime
#endif // LATINIME_CHAR_UTILS_H