icuSources/common/ustr_imp.h

   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  * NUL-terminate a UChar * string if possible.
  51  * If length  < destCapacity then NUL-terminate.
  52  * If length == destCapacity then do not terminate but set U_STRING_NOT_TERMINATED_WARNING.
  53  * If length  > destCapacity then do not terminate but set U_BUFFER_OVERFLOW_ERROR.
  54  *
  55  * @param dest Destination buffer, can be NULL if destCapacity==0.
  56  * @param destCapacity Number of UChars available at dest.
  57  * @param length Number of UChars that were (to be) written to dest.
  58  * @param pErrorCode ICU error code.
  59  * @return length
  60  */
  61 U_CAPI int32_t U_EXPORT2
  62 u_terminateUChars(UChar *dest, int32_t destCapacity, int32_t length, UErrorCode *pErrorCode);
  63
  64 /**
  65  * NUL-terminate a char * string if possible.
  66  * Same as u_terminateUChars() but for a different string type.
  67  */
  68 U_CAPI int32_t U_EXPORT2
  69 u_terminateChars(char *dest, int32_t destCapacity, int32_t length, UErrorCode *pErrorCode);
  70
  71 /**
  72  * NUL-terminate a UChar32 * string if possible.
  73  * Same as u_terminateUChars() but for a different string type.
  74  */
  75 U_CAPI int32_t U_EXPORT2
  76 u_terminateUChar32s(UChar32 *dest, int32_t destCapacity, int32_t length, UErrorCode *pErrorCode);
  77
  78 /**
  79  * NUL-terminate a wchar_t * string if possible.
  80  * Same as u_terminateUChars() but for a different string type.
  81  */
  82 U_CAPI int32_t U_EXPORT2
  83 u_terminateWChars(wchar_t *dest, int32_t destCapacity, int32_t length, UErrorCode *pErrorCode);
  84
  85 /**
  86  * Counts the bytes of any whole valid sequence for a UTF-8 lead byte.
  87  * Returns 1 for ASCII 0..0x7f.
  88  * Returns 0 for 0x80..0xc1 as well as for 0xf5..0xff.
  89  * leadByte might be evaluated multiple times.
  90  *
  91  * @param leadByte The first byte of a UTF-8 sequence. Must be 0..0xff.
  92  * @return 0..4
  93  */
  94 #define U8_COUNT_BYTES(leadByte) \
  95     (U8_IS_SINGLE(leadByte) ? 1 : U8_COUNT_BYTES_NON_ASCII(leadByte))
  96
  97 /**
  98  * Counts the bytes of any whole valid sequence for a UTF-8 lead byte.
  99  * Returns 0 for 0x00..0xc1 as well as for 0xf5..0xff.
 100  * leadByte might be evaluated multiple times.
 101  *
 102  * @param leadByte The first byte of a UTF-8 sequence. Must be 0..0xff.
 103  * @return 0 or 2..4
 104  */
 105 #define U8_COUNT_BYTES_NON_ASCII(leadByte) \
 106     (U8_IS_LEAD(leadByte) ? ((uint8_t)(leadByte)>=0xe0)+((uint8_t)(leadByte)>=0xf0)+2 : 0)
 107
 108 #ifdef __cplusplus
 109
 110 U_NAMESPACE_BEGIN
 111
 112 class UTF8 {
 113 public:
 114     UTF8() = delete;  // all static
 115
 116     /**
 117      * Is t a valid UTF-8 trail byte?
 118      *
 119      * @param prev Must be the preceding lead byte if i==1 and length>=3;
 120      *             otherwise ignored.
 121      * @param t The i-th byte following the lead byte.
 122      * @param i The index (1..3) of byte t in the byte sequence. 0<i<length
 123      * @param length The length (2..4) of the byte sequence according to the lead byte.
 124      * @return TRUE if t is a valid trail byte in this context.
 125      */
 126     static inline UBool isValidTrail(int32_t prev, uint8_t t, int32_t i, int32_t length) {
 127         // The first trail byte after a 3- or 4-byte lead byte
 128         // needs to be validated together with its lead byte.
 129         if (length <= 2 || i > 1) {
 130             return U8_IS_TRAIL(t);
 131         } else if (length == 3) {
 132             return U8_IS_VALID_LEAD3_AND_T1(prev, t);
 133         } else {  // length == 4
 134             return U8_IS_VALID_LEAD4_AND_T1(prev, t);
 135         }
 136     }
 137 };
 138
 139 U_NAMESPACE_END
 140
 141 #endif  // __cplusplus
 142
 143 /**
 144  * Check whether a code point has the emoji property.
 145  * (implemented in uchar.cpp as reduced version of u_hasBinaryProperty)
 146  *
 147  * @param c Code point to test.
 148  * @return TRUE or FALSE according to whether c has the emoji property.
 149  *
 150  * @internal Apple only
 151  */
 152 U_CAPI UBool U_EXPORT2
 153 u_isEmoji(UChar32 c);
 154
 155
 156 #endif