#include "unicode/utypes.h"
Go to the source code of this file.
Typedefs | |
typedef UNormalizationMode | UNormalizationOption |
Possible normalization options. More... | |
Enumerations | |
enum | UNormalizationMode { UCOL_NO_NORMALIZATION = 1, UCOL_DECOMP_CAN = 2, UCOL_DECOMP_COMPAT = 3, UCOL_DEFAULT_NORMALIZATION = UCOL_DECOMP_COMPAT, UCOL_DECOMP_CAN_COMP_COMPAT = 4, UCOL_DECOMP_COMPAT_COMP_CAN = 5, UNORM_NONE = 1, UNORM_NFD = 2, UNORM_NFKD = 3, UNORM_NFC = 4, UNORM_DEFAULT = UNORM_NFC, UNORM_NFKC = 5, UNORM_MODE_COUNT, UCOL_IGNORE_HANGUL = 16, UNORM_IGNORE_HANGUL = 16 } |
UCOL_NO_NORMALIZATION : Accented characters will not be decomposed for sorting. More... | |
Functions | |
U_CAPI int32_t | u_normalize (const UChar* source, int32_t sourceLength, UNormalizationMode mode, int32_t options, UChar* result, int32_t resultLength, UErrorCode* status) |
Normalize a string. More... |
u_normalize
transforms Unicode text into an equivalent composed or decomposed form, allowing for easier sorting and searching of text. u_normalize
supports the standard normalization forms described in
Unicode Technical Report #15.
Characters with accents or other adornments can be encoded in several different ways in Unicode. For example, take the character "Á" (A-acute). In Unicode, this can be encoded as a single character (the "composed" form):
or as two separate characters (the "decomposed" form):00C1 LATIN CAPITAL LETTER A WITH ACUTE
0041 LATIN CAPITAL LETTER A 0301 COMBINING ACUTE ACCENT</PRE>
To a user of your program, however, both of these sequences should be treated as the same "user-level" character "Á". When you are searching or comparing text, you must ensure that these two sequences are treated equivalently. In addition, you must handle characters with more than one accent. Sometimes the order of a character's combining accents is significant, while in other cases accent sequences in different orders are really equivalent.
Similarly, the string "ffi" can be encoded as three separate letters:
or as the single character0066 LATIN SMALL LETTER F 0066 LATIN SMALL LETTER F 0069 LATIN SMALL LETTER I
FB03 LATIN SMALL LIGATURE FFI</PRE>
The ffi ligature is not a distinct semantic character, and strictly speaking it shouldn't be in Unicode at all, but it was included for compatibility with existing character sets that already provided it. The Unicode standard identifies such characters by giving them "compatibility" decompositions into the corresponding semantic characters. When sorting and searching, you will often want to use these mappings.
u_normalize
helps solve these problems by transforming text into the
canonical composed and decomposed forms as shown in the first example above.
In addition, you can have it perform compatibility decompositions so that
you can treat compatibility characters the same as their equivalents.
Finally, u_normalize
rearranges accents into the proper canonical
order, so that you do not have to worry about accent rearrangement on your
own.
u_normalize
adds one optional behavior, #UCOL_IGNORE_HANGUL,
that differs from
the standard Unicode Normalization Forms.
Definition in file unorm.h.
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Possible normalization options.
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UCOL_NO_NORMALIZATION : Accented characters will not be decomposed for sorting. UCOL_DECOM_CAN : Characters that are canonical variants according to Unicode 2.0 will be decomposed for sorting. UCOL_DECOMP_COMPAT : Characters that are compatibility variants will be decomposed for sorting. This is the default normalization mode used. UCOL_DECOMP_CAN_COMP_COMPAT : Canonical decomposition followed by canonical composition UCOL_DECOMP_COMPAT_COMP_CAN : Compatibility decomposition followed by canonical composition
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Normalize a string. The string will be normalized according the the specified normalization mode and options.
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