scuffed-code/icu4c/source/common/unicode/normlzr.h
2000-03-22 18:31:40 +00:00

777 lines
27 KiB
C++

/*
********************************************************************
* COPYRIGHT:
* Copyright (c) 1996-1999, International Business Machines Corporation and
* others. All Rights Reserved.
********************************************************************
*/
#ifndef NORMLZR_H
#define NORMLZR_H
#include "unicode/utypes.h"
#include "unicode/unistr.h"
#include "unicode/chariter.h"
/* forward declaration */
class ComposedCharIter;
/**
* <tt>Normalizer</tt> transforms Unicode text into an equivalent composed or
* decomposed form, allowing for easier sorting and searching of text.
* <tt>Normalizer</tt> supports the standard normalization forms described in
* <a href="http://www.unicode.org/unicode/reports/tr15/" target="unicode">
* Unicode Technical Report #15</a>.
* <p>
* 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):
* <pre>
* 00C1 LATIN CAPITAL LETTER A WITH ACUTE</pre>
* or as two separate characters (the "decomposed" form):
* <pre>
* 0041 LATIN CAPITAL LETTER A
* 0301 COMBINING ACUTE ACCENT</pre>
* <p>
* 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.
* <p>
* Similarly, the string "ffi" can be encoded as three separate letters:
* <pre>
* 0066 LATIN SMALL LETTER F
* 0066 LATIN SMALL LETTER F
* 0069 LATIN SMALL LETTER I</pre>
* or as the single character
* <pre>
* FB03 LATIN SMALL LIGATURE FFI</pre>
* <p>
* 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.
* <p>
* <tt>Normalizer</tt> 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, <tt>Normalizer</tt> rearranges accents into the proper canonical
* order, so that you do not have to worry about accent rearrangement on your
* own.
* <p>
* <tt>Normalizer</tt> adds one optional behavior, {@link #IGNORE_HANGUL},
* that differs from
* the standard Unicode Normalization Forms. This option can be passed
* to the {@link #Normalizer constructors} and to the static
* {@link #compose compose} and {@link #decompose decompose} methods. This
* option, and any that are added in the future, will be turned off by default.
* <p>
* There are three common usage models for <tt>Normalizer</tt>. In the first,
* the static {@link #normalize normalize()} method is used to process an
* entire input string at once. Second, you can create a <tt>Normalizer</tt>
* object and use it to iterate through the normalized form of a string by
* calling {@link #first} and {@link #next}. Finally, you can use the
* {@link #setIndex setIndex()} and {@link #getIndex} methods to perform
* random-access iteration, which is very useful for searching.
* <p>
* <b>Note:</b> <tt>Normalizer</tt> objects behave like iterators and have
* methods such as <tt>setIndex</tt>, <tt>next</tt>, <tt>previous</tt>, etc.
* You should note that while the <tt>setIndex</tt> and <tt>getIndex</tt> refer
* to indices in the underlying <em>input</em> text being processed, the
* <tt>next</tt> and <tt>previous</tt> methods it iterate through characters
* in the normalized <em>output</em>. This means that there is not
* necessarily a one-to-one correspondence between characters returned
* by <tt>next</tt> and <tt>previous</tt> and the indices passed to and
* returned from <tt>setIndex</tt> and <tt>getIndex</tt>. It is for this
* reason that <tt>Normalizer</tt> does not implement the
* {@link CharacterIterator} interface.
* <p>
* <b>Note:</b> <tt>Normalizer</tt> is currently based on version 2.1.8
* of the <a href="http://www.unicode.org" target="unicode">Unicode Standard</a>.
* It will be updated as later versions of Unicode are released. If you are
* using this class on a JDK that supports an earlier version of Unicode, it
* is possible that <tt>Normalizer</tt> may generate composed or dedecomposed
* characters for which your JDK's {@link java.lang.Character} class does not
* have any data.
* <p>
* @author Laura Werner, Mark Davis
*/
class U_COMMON_API Normalizer
{
public:
// This tells us what the bits in the "mode" mean.
enum {
COMPAT_BIT = 1,
DECOMP_BIT = 2,
COMPOSE_BIT = 4
};
/** */
static const UChar DONE;
/** The mode of a Normalizer object */
enum EMode {
/**
* Null operation for use with the {@link #Normalizer constructors}
* and the static {@link #normalize normalize} method. This value tells
* the <tt>Normalizer</tt> to do nothing but return unprocessed characters
* from the underlying String or CharacterIterator. If you have code which
* requires raw text at some times and normalized text at others, you can
* use <tt>NO_OP</tt> for the cases where you want raw text, rather
* than having a separate code path that bypasses <tt>Normalizer</tt>
* altogether.
* <p>
* @see #setMode
*/
NO_OP = 0,
/**
* Canonical decomposition followed by canonical composition. Used with
* the {@link #Normalizer constructors} and the static
* {@link #normalize normalize}
* method to determine the operation to be performed.
* <p>
* If all optional features (<i>e.g.</i> {@link #IGNORE_HANGUL}) are turned
* off, this operation produces output that is in
* <a href=http://www.unicode.org/unicode/reports/tr15/>Unicode Canonical
* Form</a>
* <b>C</b>.
* <p>
* @see #setMode
*/
COMPOSE = COMPOSE_BIT,
/**
* Compatibility decomposition followed by canonical composition.
* Used with the {@link #Normalizer constructors} and the static
* {@link #normalize normalize} method to determine the operation to be
* performed.
* <p>
* If all optional features (<i>e.g.</i> {@link #IGNORE_HANGUL}) are turned
* off, this operation produces output that is in
* <a href=http://www.unicode.org/unicode/reports/tr15/>Unicode Canonical
* Form</a>
* <b>KC</b>.
* <p>
* @see #setMode
*/
COMPOSE_COMPAT = COMPOSE_BIT | COMPAT_BIT,
/**
* Canonical decomposition. This value is passed to the
* {@link #Normalizer constructors} and the static
* {@link #normalize normalize}
* method to determine the operation to be performed.
* <p>
* If all optional features (<i>e.g.</i> {@link #IGNORE_HANGUL}) are turned
* off, this operation produces output that is in
* <a href=http://www.unicode.org/unicode/reports/tr15/>Unicode Canonical
* Form</a>
* <b>D</b>.
* <p>
* @see #setMode
*/
DECOMP = DECOMP_BIT,
/**
* Compatibility decomposition. This value is passed to the
* {@link #Normalizer constructors} and the static
* {@link #normalize normalize}
* method to determine the operation to be performed.
* <p>
* If all optional features (<i>e.g.</i> {@link #IGNORE_HANGUL}) are turned
* off, this operation produces output that is in
* <a href=http://www.unicode.org/unicode/reports/tr15/>Unicode Canonical
* Form</a>
* <b>KD</b>.
* <p>
* @see #setMode
*/
DECOMP_COMPAT = DECOMP_BIT | COMPAT_BIT
};
/** The options for a Normalizer object */
enum {
/**
* Option to disable Hangul/Jamo composition and decomposition.
* This option applies to Korean text,
* which can be represented either in the Jamo alphabet or in Hangul
* characters, which are really just two or three Jamo combined
* into one visual glyph. Since Jamo takes up more storage space than
* Hangul, applications that process only Hangul text may wish to turn
* this option on when decomposing text.
* <p>
* The Unicode standard treates Hangul to Jamo conversion as a
* canonical decomposition, so this option must be turned <b>off</b> if you
* wish to transform strings into one of the standard
* <a href="http://www.unicode.org/unicode/reports/tr15/" target="unicode">
* Unicode Normalization Forms</a>.
* <p>
* @see #setOption
*/
IGNORE_HANGUL = 0x001
};
// Constructors
/**
* Creates a new <tt>Normalizer</tt> object for iterating over the
* normalized form of a given string.
* <p>
* @param str The string to be normalized. The normalization
* will start at the beginning of the string.
*
* @param mode The normalization mode.
* @stable
*/
Normalizer(const UnicodeString& str,
EMode mode);
/**
* Creates a new <tt>Normalizer</tt> object for iterating over the
* normalized form of a given string.
* <p>
* The <tt>options</tt> parameter specifies which optional
* <tt>Normalizer</tt> features are to be enabled for this object.
* <p>
* @param str The string to be normalized. The normalization
* will start at the beginning of the string.
*
* @param mode The normalization mode.
*
* @param opt Any optional features to be enabled.
* Currently the only available option is {@link #IGNORE_HANGUL}
* If you want the default behavior corresponding to one of the
* standard Unicode Normalization Forms, use 0 for this argument
* @stable
*/
Normalizer(const UnicodeString& str,
EMode mode,
int32_t opt);
/**
* Creates a new <tt>Normalizer</tt> object for iterating over the
* normalized form of a given UChar string.
* <p>
* @param str The string to be normalized. The normalization
* will start at the beginning of the string.
*
* @param length Lenght of the string
* @param mode The normalization mode.
* @stable
*
*/
Normalizer(const UChar* str,
int32_t length,
EMode mode);
/**
* Creates a new <tt>Normalizer</tt> object for iterating over the
* normalized form of a given UChar string.
* <p>
* @param str The string to be normalized. The normalization
* will start at the beginning of the string.
*
* @param length Lenght of the string
* @param mode The normalization mode.
* @param opt Any optional features to be enabled.
* Currently the only available option is {@link #IGNORE_HANGUL}
* If you want the default behavior corresponding to one of the
* standard Unicode Normalization Forms, use 0 for this argument
* @add
*
*/
Normalizer(const UChar* str,
int32_t length,
EMode mode,
int32_t option);
/**
* Creates a new <tt>Normalizer</tt> object for iterating over the
* normalized form of the given text.
* <p>
* @param iter The input text to be normalized. The normalization
* will start at the beginning of the string.
*
* @param mode The normalization mode.
* @stable
*
*/
Normalizer(const CharacterIterator& iter,
EMode mode);
/**
* Creates a new <tt>Normalizer</tt> object for iterating over the
* normalized form of the given text.
* <p>
* @param iter The input text to be normalized. The normalization
* will start at the beginning of the string.
*
* @param mode The normalization mode.
*
* @param opt Any optional features to be enabled.
* Currently the only available option is {@link #IGNORE_HANGUL}
* If you want the default behavior corresponding to one of the
* standard Unicode Normalization Forms, use 0 for this argument
* @stable
*/
Normalizer(const CharacterIterator& iter,
EMode mode,
int32_t opt);
/**
* Copy constructor.
* @stable
*/
Normalizer(const Normalizer& copy);
/**
* Destructor
* @stable
*/
~Normalizer();
//-------------------------------------------------------------------------
// Static utility methods
//-------------------------------------------------------------------------
/**
* Normalizes a <tt>String</tt> using the given normalization operation.
* <p>
* The <tt>options</tt> parameter specifies which optional
* <tt>Normalizer</tt> features are to be enabled for this operation.
* Currently the only available option is {@link #IGNORE_HANGUL}.
* If you want the default behavior corresponding to one of the standard
* Unicode Normalization Forms, use 0 for this argument.
* <p>
* @param source the input string to be normalized.
*
* @param aMode the normalization mode
*
* @param options the optional features to be enabled.
*
* @param result The normalized string (on output).
*
* @param status The error code.
* @stable
*/
static void normalize(const UnicodeString& source,
EMode mode,
int32_t options,
UnicodeString& result,
UErrorCode &status);
/**
* Compose a <tt>String</tt>.
* <p>
* The <tt>options</tt> parameter specifies which optional
* <tt>Normalizer</tt> features are to be enabled for this operation.
* Currently the only available option is {@link #IGNORE_HANGUL}.
* If you want the default behavior corresponding
* to Unicode Normalization Form <b>C</b> or <b>KC</b>,
* use 0 for this argument.
* <p>
* @param source the string to be composed.
*
* @param compat Perform compatibility decomposition before composition.
* If this argument is <tt>false</tt>, only canonical
* decomposition will be performed.
*
* @param options the optional features to be enabled.
*
* @param result The composed string (on output).
*
* @param status The error code.
* @stable
*/
static void compose(const UnicodeString& source,
bool_t compat,
int32_t options,
UnicodeString& result,
UErrorCode &status);
/**
* Static method to decompose a <tt>String</tt>.
* <p>
* The <tt>options</tt> parameter specifies which optional
* <tt>Normalizer</tt> features are to be enabled for this operation.
* Currently the only available option is {@link #IGNORE_HANGUL}.
* The desired options should be OR'ed together to determine the value
* of this argument. If you want the default behavior corresponding
* to Unicode Normalization Form <b>D</b> or <b>KD</b>,
* use 0 for this argument.
* <p>
* @param str the string to be decomposed.
*
* @param compat Perform compatibility decomposition.
* If this argument is <tt>false</tt>, only canonical
* decomposition will be performed.
*
* @param options the optional features to be enabled.
*
* @param result The composed string (on output).
*
* @param status The error code.
*
* @return the decomposed string.
* @stable
*/
static void decompose(const UnicodeString& source,
bool_t compat,
int32_t options,
UnicodeString& result,
UErrorCode &status);
//-------------------------------------------------------------------------
// CharacterIterator overrides
//-------------------------------------------------------------------------
/**
* Return the current character in the normalized text.
* @draft
*/
UChar current(void) const;
/**
* Return the first character in the normalized text. This resets
* the <tt>Normalizer's</tt> position to the beginning of the text.
* @draft
*/
UChar first(void);
/**
* Return the last character in the normalized text. This resets
* the <tt>Normalizer's</tt> position to be just before the
* the input text corresponding to that normalized character.
* @draft
*/
UChar last(void);
/**
* Return the next character in the normalized text and advance
* the iteration position by one. If the end
* of the text has already been reached, {@link #DONE} is returned.
* @draft
*/
UChar next(void);
/**
* Return the previous character in the normalized text and decrement
* the iteration position by one. If the beginning
* of the text has already been reached, {@link #DONE} is returned.
* @draft
*/
UChar previous(void);
/**
* Set the iteration position in the input text that is being normalized
* and return the first normalized character at that position.
* <p>
* <b>Note:</b> This method sets the position in the <em>input</em> text,
* while {@link #next} and {@link #previous} iterate through characters
* in the normalized <em>output</em>. This means that there is not
* necessarily a one-to-one correspondence between characters returned
* by <tt>next</tt> and <tt>previous</tt> and the indices passed to and
* returned from <tt>setIndex</tt> and {@link #getIndex}.
* <p>
* @param index the desired index in the input text.
*
* @return the first normalized character that is the result of iterating
* forward starting at the given index.
* @draft
*/
UChar setIndex(UTextOffset index);
/**
* Reset the iterator so that it is in the same state that it was just after
* it was constructed. A subsequent call to <tt>next</tt> will return the first
* character in the normalized text. In contrast, calling <tt>setIndex(0)</tt> followed
* by <tt>next</tt> will return the <em>second</em> character in the normalized text,
* because <tt>setIndex</tt> itself returns the first character
* @stable
*/
void reset(void);
/**
* Retrieve the current iteration position in the input text that is
* being normalized. This method is useful in applications such as
* searching, where you need to be able to determine the position in
* the input text that corresponds to a given normalized output character.
* <p>
* <b>Note:</b> This method sets the position in the <em>input</em>, while
* {@link #next} and {@link #previous} iterate through characters in the
* <em>output</em>. This means that there is not necessarily a one-to-one
* correspondence between characters returned by <tt>next</tt> and
* <tt>previous</tt> and the indices passed to and returned from
* <tt>setIndex</tt> and {@link #getIndex}.
* @stable
*/
UTextOffset getIndex(void) const;
/**
* Retrieve the index of the start of the input text. This is the begin index
* of the <tt>CharacterIterator</tt> or the start (i.e. 0) of the <tt>String</tt>
* over which this <tt>Normalizer</tt> is iterating
* @stable
*/
UTextOffset startIndex(void) const;
/**
* Retrieve the index of the end of the input text. This is the end index
* of the <tt>CharacterIterator</tt> or the length of the <tt>String</tt>
* over which this <tt>Normalizer</tt> is iterating
* @stable
*/
UTextOffset endIndex(void) const;
/**
* Returns true when both iterators refer to the same character in the same
* character-storage object.
* @stable
*/
// virtual bool_t operator==(const CharacterIterator& that) const;
bool_t operator==(const Normalizer& that) const;
inline bool_t operator!=(const Normalizer& that) const;
/**
* Returns a pointer to a new Normalizer that is a clone of this one.
* The caller is responsible for deleting the new clone.
* @stable
*/
Normalizer* clone(void) const;
/**
* Generates a hash code for this iterator.
* @stable
*/
int32_t hashCode(void) const;
//-------------------------------------------------------------------------
// Property access methods
//-------------------------------------------------------------------------
/**
* Set the normalization mode for this object.
* <p>
* <b>Note:</b>If the normalization mode is changed while iterating
* over a string, calls to {@link #next} and {@link #previous} may
* return previously buffers characters in the old normalization mode
* until the iteration is able to re-sync at the next base character.
* It is safest to call {@link #setText setText()}, {@link #first},
* {@link #last}, etc. after calling <tt>setMode</tt>.
* <p>
* @param newMode the new mode for this <tt>Normalizer</tt>.
* The supported modes are:
* <ul>
* <li>{@link #COMPOSE} - Unicode canonical decompositiion
* followed by canonical composition.
* <li>{@link #COMPOSE_COMPAT} - Unicode compatibility decompositiion
* follwed by canonical composition.
* <li>{@link #DECOMP} - Unicode canonical decomposition
* <li>{@link #DECOMP_COMPAT} - Unicode compatibility decomposition.
* <li>{@link #NO_OP} - Do nothing but return characters
* from the underlying input text.
* </ul>
*
* @see #getMode
* @stable
*/
void setMode(EMode newMode);
/**
* Return the basic operation performed by this <tt>Normalizer</tt>
*
* @see #setMode
* @stable
*/
EMode getMode(void) const;
/**
* Set options that affect this <tt>Normalizer</tt>'s operation.
* Options do not change the basic composition or decomposition operation
* that is being performed , but they control whether
* certain optional portions of the operation are done.
* Currently the only available option is:
* <p>
* <ul>
* <li>{@link #IGNORE_HANGUL} - Do not decompose Hangul syllables into the
* Jamo alphabet and vice-versa. This option is off by default
* (<i>i.e.</i> Hangul processing is enabled) since the Unicode
* standard specifies that Hangul to Jamo is a canonical decomposition.
* For any of the standard Unicode Normalization
* Forms, you should leave this option off.
* </ul>
* <p>
* @param option the option whose value is to be set.
* @param value the new setting for the option. Use <tt>true</tt> to
* turn the option on and <tt>false</tt> to turn it off.
*
* @see #getOption
* @stable
*/
void setOption(int32_t option,
bool_t value);
/**
* Determine whether an option is turned on or off.
* <p>
* @see #setOption
* @stable
*/
bool_t getOption(int32_t option) const;
/**
* Set the input text over which this <tt>Normalizer</tt> will iterate.
* The iteration position is set to the beginning.
* @stable
*/
void setText(const UnicodeString& newText,
UErrorCode &status);
/**
* Set the input text over which this <tt>Normalizer</tt> will iterate.
* The iteration position is set to the beginning.
* @stable
*/
void setText(const CharacterIterator& newText,
UErrorCode &status);
/**
* Set the input text over which this <tt>Normalizer</tt> will iterate.
* The iteration position is set to the beginning.
* @stable
*/
void setText(const UChar* newText,
int32_t length,
UErrorCode &status);
/**
* Copies the text under iteration into the UnicodeString referred to by
* "result".
* @param result Receives a copy of the text under iteration.
* @draft should also return the result UnicodeString &
*/
void getText(UnicodeString& result);
/**
* Returns the text under iteration into the UChar* buffer pointer.
* @param result Receives a copy of the text under iteration.
* @add
*/
const UChar* getText(int32_t& count);
private:
// Private utility methods for iteration
// For documentation, see the source code
UChar nextCompose(void);
UChar prevCompose(void);
UChar nextDecomp(void);
UChar prevDecomp(void);
UChar curForward(void);
UChar curBackward(void);
void init(CharacterIterator* iter,
EMode mode,
int32_t option);
void initBuffer(void);
void clearBuffer(void);
// Utilities used by Compose
static void bubbleAppend(UnicodeString& target,
UChar ch,
uint32_t cclass);
static uint32_t getComposeClass(UChar ch);
static uint16_t composeLookup(UChar ch);
static uint16_t composeAction(uint16_t baseIndex,
uint16_t comIndex);
static void explode(UnicodeString& target,
uint16_t index);
static UChar pairExplode(UnicodeString& target,
uint16_t action);
// Utilities used by Decompose
static void fixCanonical(UnicodeString& result); // Reorders combining marks
static uint8_t getClass(UChar ch); // Gets char's combining class
// Other static utility methods
static void doAppend(const UChar source[],
uint16_t offset,
UnicodeString& dest);
static void doInsert(const UChar source[],
uint16_t offset,
UnicodeString& dest,
UTextOffset pos);
static void hangulToJamo(UChar ch,
UnicodeString& result,
uint16_t decompLimit);
static void jamoAppend(UChar ch,
uint16_t decompLimit,
UnicodeString& dest);
static void jamoToHangul(UnicodeString& buffer,
UTextOffset start);
//-------------------------------------------------------------------------
// Private data
//-------------------------------------------------------------------------
EMode fMode;
int32_t fOptions;
int16_t minDecomp;
// The input text and our position in it
CharacterIterator* text;
// A buffer for holding intermediate results
UnicodeString buffer;
UTextOffset bufferPos;
UTextOffset bufferLimit;
UChar currentChar;
// Another buffer for use during iterative composition
UnicodeString explodeBuf;
enum {
EMPTY = -1,
STR_INDEX_SHIFT = 2, //Must agree with the constants used in NormalizerBuilder
STR_LENGTH_MASK = 0x0003
};
static const UChar HANGUL_BASE;
static const UChar HANGUL_LIMIT;
static const UChar JAMO_LBASE;
static const UChar JAMO_VBASE;
static const UChar JAMO_TBASE;
static const int16_t JAMO_LCOUNT;
static const int16_t JAMO_VCOUNT;
static const int16_t JAMO_TCOUNT;
static const int16_t JAMO_NCOUNT;
friend class ComposedCharIter;
};
inline bool_t
Normalizer::operator!= (const Normalizer& other) const
{ return ! operator==(other); }
#endif // _NORMLZR