ustr_imp.h (5068B)
1 // © 2016 and later: Unicode, Inc. and others. 2 // License & terms of use: http://www.unicode.org/copyright.html 3 /* 4 ********************************************************************** 5 * Copyright (C) 1999-2015, International Business Machines 6 * Corporation and others. All Rights Reserved. 7 ********************************************************************** 8 * file name: ustr_imp.h 9 * encoding: UTF-8 10 * tab size: 8 (not used) 11 * indentation:4 12 * 13 * created on: 2001jan30 14 * created by: Markus W. Scherer 15 */ 16 17 #ifndef __USTR_IMP_H__ 18 #define __USTR_IMP_H__ 19 20 #include "unicode/utypes.h" 21 #include "unicode/utf8.h" 22 23 /** 24 * Internal option for unorm_cmpEquivFold() for strncmp style. 25 * If set, checks for both string length and terminating NUL. 26 */ 27 #define _STRNCMP_STYLE 0x1000 28 29 /** 30 * Compare two strings in code point order or code unit order. 31 * Works in strcmp style (both lengths -1), 32 * strncmp style (lengths equal and >=0, flag true), 33 * and memcmp/UnicodeString style (at least one length >=0). 34 */ 35 U_CFUNC int32_t U_EXPORT2 36 uprv_strCompare(const UChar *s1, int32_t length1, 37 const UChar *s2, int32_t length2, 38 UBool strncmpStyle, UBool codePointOrder); 39 40 U_CAPI int32_t U_EXPORT2 41 ustr_hashUCharsN(const UChar *str, int32_t length); 42 43 U_CAPI int32_t U_EXPORT2 44 ustr_hashCharsN(const char *str, int32_t length); 45 46 U_CAPI int32_t U_EXPORT2 47 ustr_hashICharsN(const char *str, int32_t length); 48 49 /** 50 * Convert an ASCII-range lowercase character to uppercase. 51 * 52 * @param c A UChar. 53 * @return If UChar is a lowercase ASCII character, returns the uppercase version. 54 * Otherwise, returns the input character. 55 */ 56 U_CAPI UChar U_EXPORT2 57 u_asciiToUpper(UChar c); 58 59 // TODO: Add u_asciiToLower if/when there is a need for it. 60 61 /** 62 * NUL-terminate a UChar * string if possible. 63 * If length < destCapacity then NUL-terminate. 64 * If length == destCapacity then do not terminate but set U_STRING_NOT_TERMINATED_WARNING. 65 * If length > destCapacity then do not terminate but set U_BUFFER_OVERFLOW_ERROR. 66 * 67 * @param dest Destination buffer, can be NULL if destCapacity==0. 68 * @param destCapacity Number of UChars available at dest. 69 * @param length Number of UChars that were (to be) written to dest. 70 * @param pErrorCode ICU error code. 71 * @return length 72 */ 73 U_CAPI int32_t U_EXPORT2 74 u_terminateUChars(UChar *dest, int32_t destCapacity, int32_t length, UErrorCode *pErrorCode); 75 76 /** 77 * NUL-terminate a char * string if possible. 78 * Same as u_terminateUChars() but for a different string type. 79 */ 80 U_CAPI int32_t U_EXPORT2 81 u_terminateChars(char *dest, int32_t destCapacity, int32_t length, UErrorCode *pErrorCode); 82 83 /** 84 * NUL-terminate a UChar32 * string if possible. 85 * Same as u_terminateUChars() but for a different string type. 86 */ 87 U_CAPI int32_t U_EXPORT2 88 u_terminateUChar32s(UChar32 *dest, int32_t destCapacity, int32_t length, UErrorCode *pErrorCode); 89 90 /** 91 * NUL-terminate a wchar_t * string if possible. 92 * Same as u_terminateUChars() but for a different string type. 93 */ 94 U_CAPI int32_t U_EXPORT2 95 u_terminateWChars(wchar_t *dest, int32_t destCapacity, int32_t length, UErrorCode *pErrorCode); 96 97 /** 98 * Counts the bytes of any whole valid sequence for a UTF-8 lead byte. 99 * Returns 1 for ASCII 0..0x7f. 100 * Returns 0 for 0x80..0xc1 as well as for 0xf5..0xff. 101 * leadByte might be evaluated multiple times. 102 * 103 * @param leadByte The first byte of a UTF-8 sequence. Must be 0..0xff. 104 * @return 0..4 105 */ 106 #define U8_COUNT_BYTES(leadByte) \ 107 (U8_IS_SINGLE(leadByte) ? 1 : U8_COUNT_BYTES_NON_ASCII(leadByte)) 108 109 /** 110 * Counts the bytes of any whole valid sequence for a UTF-8 lead byte. 111 * Returns 0 for 0x00..0xc1 as well as for 0xf5..0xff. 112 * leadByte might be evaluated multiple times. 113 * 114 * @param leadByte The first byte of a UTF-8 sequence. Must be 0..0xff. 115 * @return 0 or 2..4 116 */ 117 #define U8_COUNT_BYTES_NON_ASCII(leadByte) \ 118 (U8_IS_LEAD(leadByte) ? ((uint8_t)(leadByte)>=0xe0)+((uint8_t)(leadByte)>=0xf0)+2 : 0) 119 120 #ifdef __cplusplus 121 122 U_NAMESPACE_BEGIN 123 124 class UTF8 { 125 public: 126 UTF8() = delete; // all static 127 128 /** 129 * Is t a valid UTF-8 trail byte? 130 * 131 * @param prev Must be the preceding lead byte if i==1 and length>=3; 132 * otherwise ignored. 133 * @param t The i-th byte following the lead byte. 134 * @param i The index (1..3) of byte t in the byte sequence. 0<i<length 135 * @param length The length (2..4) of the byte sequence according to the lead byte. 136 * @return true if t is a valid trail byte in this context. 137 */ 138 static inline UBool isValidTrail(int32_t prev, uint8_t t, int32_t i, int32_t length) { 139 // The first trail byte after a 3- or 4-byte lead byte 140 // needs to be validated together with its lead byte. 141 if (length <= 2 || i > 1) { 142 return U8_IS_TRAIL(t); 143 } else if (length == 3) { 144 return U8_IS_VALID_LEAD3_AND_T1(prev, t); 145 } else { // length == 4 146 return U8_IS_VALID_LEAD4_AND_T1(prev, t); 147 } 148 } 149 }; 150 151 U_NAMESPACE_END 152 153 #endif // __cplusplus 154 155 #endif