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UNormalize Class Reference

Inheritance diagram for UNormalize:

ICU List of all members.

Public Types

enum  Mode {
  None = 1, NFD = 2, NFKD = 3, NFC = 4,
  Default = NFC, NFKC = 5, FCD = 6, Count
}
enum  Check { No, Yes, Maybe }
enum  Options { None = 1, Unicode32 = 0x20 }

Static Public Member Functions

void normalize (UText src, UString dst, Mode mode, Options o=Options.None)
Check check (UText t, Mode mode, Options o=Options.None)
bool isNormalized (UText t, Mode mode, Options o=Options.None)
void concatenate (UText left, UText right, UString dst, Mode mode, Options o=Options.None)
int compare (UText left, UText right, Options o=Options.None)
 this ()
 ~this ()

Static Public Attributes

FunctionLoader Bind[] targets

Private Types

typedef void * Handle
enum  Error { OK, BufferOverflow = 15 }

Static Private Member Functions

bool isError (Error e)
void testError (Error e, char[] msg)
char * toString (char[] string)
wchar * toString (wchar[] string)
uint length (char *s)
uint length (wchar *s)
char[] toArray (char *s)
wchar[] toArray (wchar *s)

Static Private Attributes

void * library

Detailed Description

transforms Unicode text into an equivalent composed or decomposed form, allowing for easier sorting and searching of text. UNormalize supports the standard normalization forms described in http://www.unicode.org/unicode/reports/tr15/

Characters with accents or other adornments can be encoded in several different ways in Unicode. For example, take the character A-acute. In Unicode, this can be encoded as a single character (the "composed" form):

00C1 LATIN CAPITAL LETTER A WITH ACUTE

or as two separate characters (the "decomposed" form):

0041 LATIN CAPITAL LETTER A 0301 COMBINING ACUTE ACCENT

To a user of your program, however, both of these sequences should be treated as the same "user-level" character "A with acute accent". 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:

0066 LATIN SMALL LETTER F 0066 LATIN SMALL LETTER F 0069 LATIN SMALL LETTER I

or as the single character

FB03 LATIN SMALL LIGATURE FFI

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.

unorm_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, UNormalize rearranges accents into the proper canonical order, so that you do not have to worry about accent rearrangement on your own.

Form FCD, "Fast C or D", is also designed for collation. It allows to work on strings that are not necessarily normalized with an algorithm (like in collation) that works under "canonical closure", i.e., it treats precomposed characters and their decomposed equivalents the same.

It is not a normalization form because it does not provide for uniqueness of representation. Multiple strings may be canonically equivalent (their NFDs are identical) and may all conform to FCD without being identical themselves.

The form is defined such that the "raw decomposition", the recursive canonical decomposition of each character, results in a string that is canonically ordered. This means that precomposed characters are allowed for as long as their decompositions do not need canonical reordering.

Its advantage for a process like collation is that all NFD and most NFC texts - and many unnormalized texts - already conform to FCD and do not need to be normalized (NFD) for such a process. The FCD quick check will return UNORM_YES for most strings in practice.

For more details on FCD see the collation design document: http://oss.software.ibm.com/cvs/icu/~checkout~/icuhtml/design/collation/ICU_collation_design.htm

ICU collation performs either NFD or FCD normalization automatically if normalization is turned on for the collator object. Beyond collation and string search, normalized strings may be useful for string equivalence comparisons, transliteration/ transcription, unique representations, etc.

The W3C generally recommends to exchange texts in NFC. Note also that most legacy character encodings use only precomposed forms and often do not encode any combining marks by themselves. For conversion to such character encodings the Unicode text needs to be normalized to NFC. For more usage examples, see the Unicode Standard Annex.

See this page for full details.

Definition at line 189 of file UNormalize.d.


Member Typedef Documentation

typedef void* Handle [protected, inherited]
 

Use this for the primary argument-type to most ICU functions

Definition at line 63 of file ICU.d.


Member Enumeration Documentation

enum Mode
 

Enumeration values:
None 
NFD 
NFKD 
NFC 
Default 
NFKC 
FCD 
Count 

Definition at line 191 of file UNormalize.d.

enum Check
 

Enumeration values:
No 
Yes 
Maybe 

Definition at line 203 of file UNormalize.d.

Referenced by check().

enum Options
 

Enumeration values:
None 
Unicode32 

Definition at line 210 of file UNormalize.d.

enum Error [protected, inherited]
 

ICU error codes (the ones which are referenced)

Enumeration values:
OK 
BufferOverflow 

Definition at line 100 of file ICU.d.


Constructor & Destructor Documentation

~this  )  [inline, static]
 

Definition at line 387 of file UNormalize.d.


Member Function Documentation

void normalize UText  src,
UString  dst,
Mode  mode,
Options  o = Options.None
[inline, static]
 

Normalize a string. The string will be normalized according the specified normalization mode and options

Definition at line 223 of file UNormalize.d.

References UText::get(), and UText::len.

Check check UText  t,
Mode  mode,
Options  o = Options.None
[inline, static]
 

Performing quick check on a string, to quickly determine if the string is in a particular normalization format.

Three types of result can be returned: Yes, No or Maybe. Result Yes indicates that the argument string is in the desired normalized format, No determines that argument string is not in the desired normalized format. A Maybe result indicates that a more thorough check is required, the user may have to put the string in its normalized form and compare the results.

Definition at line 248 of file UNormalize.d.

References Check, UText::get(), UText::len, and ICU::testError().

bool isNormalized UText  t,
Mode  mode,
Options  o = Options.None
[inline, static]
 

Test if a string is in a given normalization form.

Unlike check(), this function returns a definitive result, never a "maybe". For NFD, NFKD, and FCD, both functions work exactly the same. For NFC and NFKC where quickCheck may return "maybe", this function will perform further tests to arrive at a TRUE/FALSE result.

Definition at line 269 of file UNormalize.d.

References UText::get(), UText::len, and ICU::testError().

void concatenate UText  left,
UText  right,
UString  dst,
Mode  mode,
Options  o = Options.None
[inline, static]
 

Concatenate normalized strings, making sure that the result is normalized as well. If both the left and the right strings are in the normalization form according to "mode/options", then the result will be

dest=normalize(left+right, mode, options)

With the input strings already being normalized, this function will use unorm_next() and unorm_previous() to find the adjacent end pieces of the input strings. Only the concatenation of these end pieces will be normalized and then concatenated with the remaining parts of the input strings.

It is allowed to have dst==left to avoid copying the entire left string.

Definition at line 298 of file UNormalize.d.

References UString::format(), UText::get(), and UText::len.

int compare UText  left,
UText  right,
Options  o = Options.None
[inline, static]
 

Compare two strings for canonical equivalence. Further options include case-insensitive comparison and code point order (as opposed to code unit order).

Canonical equivalence between two strings is defined as their normalized forms (NFD or NFC) being identical. This function compares strings incrementally instead of normalizing (and optionally case-folding) both strings entirely, improving performance significantly.

Bulk normalization is only necessary if the strings do not fulfill the FCD conditions. Only in this case, and only if the strings are relatively long, is memory allocated temporarily. For FCD strings and short non-FCD strings there is no memory allocation.

Definition at line 328 of file UNormalize.d.

References UText::get(), UText::len, and ICU::testError().

this  )  [inline, static]
 

Definition at line 378 of file UNormalize.d.

bool isError Error  e  )  [inline, static, protected, inherited]
 

Definition at line 110 of file ICU.d.

Referenced by UConverter::detectSignature(), UString::format(), UCollator::getLocale(), and UConverter::this().

void testError Error  e,
char[]  msg
[inline, static, protected, inherited]
 

Definition at line 128 of file ICU.d.

Referenced by UCalendar::add(), USet::applyPattern(), UChar::charFromName(), check(), compare(), UDomainName::compare(), UConverter::UTranscoder::convert(), UEnumeration::count(), UConverter::decode(), UConverter::encode(), UTransform::execute(), USearch::first(), UResourceBundle::get(), UCalendar::get(), UCollator::getAttribute(), UResourceBundle::getBinary(), UCollator::getBound(), UChar::getCharName(), UChar::getComment(), UCollator::getContractions(), UResourceBundle::getInt(), UResourceBundle::getIntVector(), UCalendar::getLimit(), UResourceBundle::getLocale(), UCalendar::getMillis(), UConverter::getName(), UResourceBundle::getNextString(), UCollator::getShortDefinitionString(), UResourceBundle::getString(), UCollator::getTailoredSet(), UDateFormat::getTwoDigitYearStart(), UCollator::getVariableTop(), UCalendar::inDaylightTime(), isNormalized(), USearch::last(), USearch::next(), UEnumeration::next(), UCollator::normalizeShortDefinitionString(), UDateFormat::parse(), USearch::previous(), UEnumeration::reset(), UCalendar::roll(), UCollator::setAttribute(), USearch::setCollator(), UCalendar::setDate(), UCalendar::setDateTime(), UTransform::setFilter(), USearch::setIterator(), UCalendar::setMillis(), USearch::setOffset(), USearch::setPattern(), UDecimalFormat::setPattern(), UMessageFormat::setPattern(), USearch::setText(), UBreakIterator::setText(), UCalendar::setTimeZone(), UDateFormat::setTwoDigitYearStart(), UCollator::setVariableTop(), UTransform::this(), UStringPrep::this(), USet::this(), USearch::this(), UResourceBundle::this(), UNumberFormat::this(), UMessageFormat::this(), UDateFormat::this(), UCollator::this(), UCalendar::this(), UBreakIterator::this(), URuleIterator::this(), and UText::toUtf8().

char* toString char[]  string  )  [inline, static, protected, inherited]
 

Definition at line 138 of file ICU.d.

References string.

Referenced by UChar::charFromName(), UConverter::compareNames(), UCollator::getDisplayName(), UResourceBundle::getResource(), UCollator::getShortDefinitionString(), UResourceBundle::getString(), UCalendar::getTimeZoneName(), UCollator::normalizeShortDefinitionString(), UMessageFormat::setLocale(), UStringPrep::this(), UResourceBundle::this(), UDateFormat::this(), UCollator::this(), UBreakIterator::this(), UText::toLower(), and UText::toUpper().

wchar* toString wchar[]  string  )  [inline, static, protected, inherited]
 

Definition at line 160 of file ICU.d.

References string.

uint length char *  s  )  [inline, static, protected, inherited]
 

Definition at line 182 of file ICU.d.

References strlen().

uint length wchar *  s  )  [inline, static, protected, inherited]
 

Definition at line 191 of file ICU.d.

References wcslen().

char [] toArray char *  s  )  [inline, static, protected, inherited]
 

Definition at line 200 of file ICU.d.

References strlen().

Referenced by UConverter::detectSignature(), UResourceBundle::getKey(), UResourceBundle::getLocale(), UMessageFormat::getLocale(), UCollator::getLocale(), UConverter::getName(), UChar::getPropertyName(), UChar::getPropertyValueName(), and UConverter::opApply().

wchar [] toArray wchar *  s  )  [inline, static, protected, inherited]
 

Definition at line 211 of file ICU.d.

References wcslen().


Member Data Documentation

void* library [static, private]
 

Bind the ICU functions from a shared library. This is complicated by the issues regarding D and DLLs on the Windows platform

Definition at line 346 of file UNormalize.d.

FunctionLoader Bind [] targets [static]
 

Initial value:

 
                [
                {cast(void**) &unorm_normalize,                 "unorm_normalize"}

Definition at line 365 of file UNormalize.d.


The documentation for this class was generated from the following file:
Generated on Tue Jan 25 21:18:43 2005 for Mango by doxygen 1.3.6