scuffed-code/icu4c/source/i18n/coleitr.cpp
2000-05-24 21:01:07 +00:00

673 lines
19 KiB
C++
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/*
*******************************************************************************
* Copyright (C) 1996-1999, International Business Machines Corporation and *
* others. All Rights Reserved. *
*******************************************************************************
*/
//=============================================================================
//
// File coleitr.cpp
//
//
//
// Created by: Helena Shih
//
// Modification History:
//
// Date Name Description
//
// 6/23/97 helena Adding comments to make code more readable.
// 08/03/98 erm Synched with 1.2 version of CollationElementIterator.java
// 12/10/99 aliu Ported Thai collation support from Java.
//=============================================================================
#include "unicode/sortkey.h"
#include "unicode/coleitr.h"
#include "unicode/chariter.h"
#include "tables.h"
#include "unicode/normlzr.h"
#include "unicode/unicode.h"
#include "tcoldata.h"
#include "ucmp32.h"
int32_t const CollationElementIterator::NULLORDER = 0xffffffff;
int32_t const CollationElementIterator::UNMAPPEDCHARVALUE = 0x7fff0000;
// This private method will never be called, but it makes the linker happy
CollationElementIterator::CollationElementIterator()
: expIndex(0),
text(0),
bufferAlias(0),
ownBuffer(new VectorOfInt(2)),
reorderBuffer(0),
orderAlias(0)
{
}
// This private method will never be called, but it makes the linker happy
CollationElementIterator::CollationElementIterator(const RuleBasedCollator* order)
: expIndex(0),
text(0),
bufferAlias(0),
ownBuffer(new VectorOfInt(2)),
reorderBuffer(0),
orderAlias(order)
{
}
// This is the "real" constructor for this class; it constructs an iterator
// over the source text using the specified collator
CollationElementIterator::CollationElementIterator( const UnicodeString& sourceText,
const RuleBasedCollator* order,
UErrorCode& status)
: expIndex(0),
text(NULL),
bufferAlias(NULL),
ownBuffer(new VectorOfInt(2)),
reorderBuffer(0),
orderAlias(order)
{
if (U_FAILURE(status)) {
return;
}
if ( sourceText.length() != 0 ) {
//
// A CollationElementIterator is really a two-layered beast.
// Internally it uses a Normalizer to munge the source text
// into a form where all "composed" Unicode characters (such as <20>) are
// split into a normal character and a combining accent character.
// Afterward, CollationElementIterator does its own processing to handle
// expanding and contracting collation sequences, ignorables, and so on.
//
Normalizer::EMode decomp = (order->getStrength() == Collator::IDENTICAL)
? Normalizer::NO_OP
: order->getDecomposition();
text = new Normalizer(sourceText, decomp);
if (text == NULL) {
status = U_MEMORY_ALLOCATION_ERROR;
}
}
}
// This is the "real" constructor for this class; it constructs an iterator
// over the source text using the specified collator
CollationElementIterator::CollationElementIterator( const CharacterIterator& sourceText,
const RuleBasedCollator* order,
UErrorCode& status)
: expIndex(0),
text(NULL),
bufferAlias(NULL),
ownBuffer(new VectorOfInt(2)),
reorderBuffer(0),
orderAlias(order)
{
if (U_FAILURE(status)) {
return;
}
// **** should I just drop this test? ****
if ( sourceText.endIndex() != 0 )
{
//
// A CollationElementIterator is really a two-layered beast.
// Internally it uses a Normalizer to munge the source text
// into a form where all "composed" Unicode characters (such as <20>) are
// split into a normal character and a combining accent character.
// Afterward, CollationElementIterator does its own processing to handle
// expanding and contracting collation sequences, ignorables, and so on.
//
Normalizer::EMode decomp = order->getStrength() == Collator::IDENTICAL
? Normalizer::NO_OP
: order->getDecomposition();
text = new Normalizer(sourceText, decomp);
if (text == NULL) {
status = U_MEMORY_ALLOCATION_ERROR;
}
}
}
CollationElementIterator::CollationElementIterator(const CollationElementIterator& other)
: expIndex(other.expIndex), text(0),
ownBuffer(new VectorOfInt(2)),
reorderBuffer(0)
{
*this = other;
}
const CollationElementIterator&
CollationElementIterator::operator=(const CollationElementIterator& other)
{
if (this != &other)
{
expIndex = other.expIndex;
delete text;
text = (Normalizer*)other.text->clone();
if (other.bufferAlias == other.ownBuffer) {
*ownBuffer = *other.ownBuffer;
bufferAlias = ownBuffer;
} else if (other.bufferAlias != NULL &&
other.bufferAlias == other.reorderBuffer) {
if (reorderBuffer == NULL) {
reorderBuffer = new VectorOfInt(*other.reorderBuffer);
} else {
*reorderBuffer = *other.reorderBuffer;
}
bufferAlias = reorderBuffer;
} else {
bufferAlias = other.bufferAlias;
}
orderAlias = other.orderAlias;
}
return *this;
}
CollationElementIterator::~CollationElementIterator()
{
delete text;
text = NULL;
bufferAlias = NULL;
orderAlias = NULL;
delete ownBuffer;
delete reorderBuffer;
}
UBool
CollationElementIterator::operator==(const CollationElementIterator& that) const
{
if (this == &that)
{
return TRUE;
}
if (*text != *(that.text))
{
return FALSE;
}
if (((bufferAlias == NULL) != (that.bufferAlias == NULL)) ||
(bufferAlias != NULL && *bufferAlias != *(that.bufferAlias)))
{
return FALSE;
}
if (expIndex != that.expIndex)
{
return FALSE;
}
if (orderAlias != that.orderAlias)
{
return FALSE;
}
return TRUE;
}
UBool
CollationElementIterator::operator!=(const CollationElementIterator& other) const
{
return !(*this == other);
}
/**
* Resets the cursor to the beginning of the string.
*/
void
CollationElementIterator::reset()
{
if (text != NULL)
{
text->reset();
text->setMode(orderAlias->getDecomposition());
}
bufferAlias = NULL;
expIndex = 0;
}
// Sets the source to the new source string.
void
CollationElementIterator::setText(const UnicodeString& source,
UErrorCode& status)
{
if (U_FAILURE(status))
{
return;
}
bufferAlias = 0;
if (text == NULL)
{
text = new Normalizer(source, orderAlias->getDecomposition());
}
else
{
text->setText(source, status);
text->setMode(orderAlias->getDecomposition());
}
}
// Sets the source to the new character iterator.
void
CollationElementIterator::setText(CharacterIterator& source,
UErrorCode& status)
{
if (U_FAILURE(status)) {
return;
}
bufferAlias = 0;
if (text == NULL) {
text = new Normalizer(source, orderAlias->getDecomposition());
}
else
{
text->setMode(orderAlias->getDecomposition());
text->setText(source, status);
}
}
/**
* Get the ordering priority of the next character in the string.
* @return the next character's ordering. Returns NULLORDER if
* the end of string is reached.
*/
int32_t
CollationElementIterator::next(UErrorCode& status)
{
if (text == NULL || U_FAILURE(status))
{
return NULLORDER;
}
// Update the decomposition mode if necessary.
text->setMode(orderAlias->getDecomposition());
if (bufferAlias != NULL)
{
// bufferAlias needs a bit of an explanation.
// When we hit an expanding character in the text, we call the order's
// getExpandValues method to retrieve an array of the orderings for all
// of the characters in the expansion (see the end of this method).
// The first ordering is returned, and an alias to the orderings array
// is saved so that the remaining orderings can be returned on subsequent
// calls to next. So, if the expanding buffer is not exhausted,
// all we have to do here is return the next ordering in the buffer.
if (expIndex < bufferAlias->size())
{
return strengthOrder(bufferAlias->at(expIndex++));
}
else
{
bufferAlias = NULL;
}
}
// Gets the next character from the string using decomposition iterator.
UChar32 ch = text->current();
text->next();
if (U_FAILURE(status))
{
return NULLORDER;
}
if (ch == Normalizer::DONE)
{
return NULLORDER;
}
// Ask the collator for this character's ordering.
/* Used to be RuleBasedCollator.getUnicodeOrder(). It
can't be inlined in tblcoll.h file unfortunately. */
int32_t value = ucmp32_get(orderAlias->data->mapping, ch);
if (value == RuleBasedCollator::UNMAPPED)
{
// Returned an "unmapped" flag and save the character so it can be
// returned next time this method is called.
if (ch == 0x0000) return ch;
// \u0000 is not valid in C++'s UnicodeString
ownBuffer->at(0) = UNMAPPEDCHARVALUE;
ownBuffer->at(1) = ch << 16;
bufferAlias = ownBuffer;
}
else {
if (value >= RuleBasedCollator::CONTRACTCHARINDEX) {
value = nextContractChar(ch, status);
}
if (value >= RuleBasedCollator::EXPANDCHARINDEX) {
bufferAlias = orderAlias->getExpandValueList(value);
}
if (isThaiPreVowel(ch)) {
UChar32 consonant = text->next();
if (isThaiBaseConsonant(consonant)) {
bufferAlias = makeReorderedBuffer((UChar)consonant, value, bufferAlias,
TRUE, status);
}
else {
text->previous();
}
}
}
if (bufferAlias != NULL) {
expIndex = 1;
value = bufferAlias->at(0);
}
return strengthOrder(value);
}
/**
* Get the ordering priority of the previous collation element in the string.
* @param status the error code status.
* @return the previous element's ordering. Returns NULLORDER if
* the beginning of string is reached.
*/
int32_t
CollationElementIterator::previous(UErrorCode& status)
{
if (text == NULL || U_FAILURE(status))
{
return NULLORDER;
}
text->setMode(orderAlias->getDecomposition());
if (bufferAlias != NULL)
{
if (expIndex > 0)
{
return strengthOrder(bufferAlias->at(--expIndex));
}
bufferAlias = NULL;
}
UChar32 ch = text->previous();
if (ch == Normalizer::DONE)
{
return NULLORDER;
}
/* Used to be RuleBasedCollator.getUnicodeOrder(). It
can't be inlined in tblcoll.h file unfortunately. */
int32_t value = ucmp32_get(orderAlias->data->mapping, ch);
if (value == RuleBasedCollator::UNMAPPED)
{
if (ch == 0x0000) return ch;
ownBuffer->at(0) = UNMAPPEDCHARVALUE;
ownBuffer->at(1) = ch << 16;
bufferAlias = ownBuffer;
}
else {
if (value >= RuleBasedCollator::CONTRACTCHARINDEX) {
value = prevContractChar(ch, status);
}
if (value >= RuleBasedCollator::EXPANDCHARINDEX) {
bufferAlias = orderAlias->getExpandValueList(value);
}
if (isThaiBaseConsonant(ch)) {
UChar32 vowel = text->previous();
if (isThaiPreVowel(vowel)) {
bufferAlias = makeReorderedBuffer((UChar)vowel, value, bufferAlias,
FALSE, status);
}
else {
text->next();
}
}
}
if (bufferAlias != NULL) {
expIndex = bufferAlias->size()-1;
value = bufferAlias->at(expIndex);
}
return strengthOrder(value);
}
int32_t
CollationElementIterator::strengthOrder(int32_t order) const
{
Collator::ECollationStrength s = orderAlias->getStrength();
// Mask off the unwanted differences.
if (s == Collator::PRIMARY)
{
order &= RuleBasedCollator::PRIMARYDIFFERENCEONLY;
} else if (s == Collator::SECONDARY)
{
order &= RuleBasedCollator::SECONDARYDIFFERENCEONLY;
}
return order;
}
UTextOffset
CollationElementIterator::getOffset() const
{
// Since the DecompositionIterator is doing the work of iterating through
// the text string, we can just ask it what its offset is.
return (text != NULL) ? text->getIndex() : 0;
}
void
CollationElementIterator::setOffset(UTextOffset newOffset,
UErrorCode& status)
{
if (U_FAILURE(status))
{
return;
}
if (text != NULL)
{
text->setIndex(newOffset);
}
bufferAlias = NULL;
}
//============================================================
// privates
//============================================================
/**
* Get the ordering priority of the next contracting character in the
* string.
* @param ch the starting character of a contracting character token
* @return the next contracting character's ordering. Returns NULLORDER
* if the end of string is reached.
*/
int32_t
CollationElementIterator::nextContractChar(UChar32 ch,
UErrorCode& status)
{
// First get the ordering of this single character
VectorOfPToContractElement *list = orderAlias->getContractValues((UChar)ch);
EntryPair *pair = (EntryPair *)list->at(0);
int32_t order = pair->value;
// Now iterate through the chars following it and
// look for the longest match
key.remove();
key += ch;
while ((ch = text->current()) != Normalizer::DONE)
{
if (U_FAILURE(status))
{
return NULLORDER;
}
key += ch;
int32_t n = RuleBasedCollator::getEntry(list, key, TRUE);
if (n == RuleBasedCollator::UNMAPPED)
{
break;
}
text->next();
pair = (EntryPair *)list->at(n);
order = pair->value;
}
return order;
}
/**
* Get the ordering priority of the previous contracting character in the
* string.
* @param ch the starting character of a contracting character token
* @return the next contracting character's ordering. Returns NULLORDER
* if the end of string is reached.
*/
int32_t CollationElementIterator::prevContractChar(UChar32 ch,
UErrorCode &status)
{
// First get the ordering of this single character
VectorOfPToContractElement *list = orderAlias->getContractValues((UChar)ch);
EntryPair *pair = (EntryPair *)list->at(0);
int32_t order = pair->value;
// Now iterate through the chars following it and
// look for the longest match
key.remove();
key += ch;
while ((ch = text->previous()) != Normalizer::DONE)
{
key += ch;
int32_t n = RuleBasedCollator::getEntry(list, key, FALSE);
if (n == RuleBasedCollator::UNMAPPED)
{
ch = text->next();
if (U_FAILURE(status))
{
return NULLORDER;
}
break;
}
pair = (EntryPair *)list->at(n);
order = pair->value;
}
return order;
}
/**
* This method produces a buffer which contains the collation
* elements for the two characters, with colFirst's values preceding
* another character's. Presumably, the other character precedes colFirst
* in logical
* order (otherwise you wouldn't need this method would you?).
* The assumption is that the other char's value(s) have already been
* computed. If this char has a single element it is passed to this
* method as lastValue, and lastExpasion is null. If it has an
* expasion it is passed in lastExpansion, and colLastValue is ignored.
* This method may return the ownBuffer array as its value so ownBuffer
* had better not be in use anywhere else.
*/
VectorOfInt* CollationElementIterator::makeReorderedBuffer(UChar colFirst,
int32_t lastValue,
VectorOfInt* lastExpansion,
UBool forward,
UErrorCode& status) {
VectorOfInt* result;
int32_t firstValue = ucmp32_get(orderAlias->data->mapping, colFirst);
if (firstValue >= RuleBasedCollator::CONTRACTCHARINDEX) {
firstValue = forward ? nextContractChar(colFirst, status)
: prevContractChar(colFirst, status);
}
VectorOfInt* firstExpansion = NULL;
if (firstValue >= RuleBasedCollator::EXPANDCHARINDEX) {
firstExpansion = orderAlias->getExpandValueList(firstValue);
}
if (!forward) {
int32_t temp1 = firstValue;
firstValue = lastValue;
lastValue = temp1;
VectorOfInt* temp2 = firstExpansion;
firstExpansion = lastExpansion;
lastExpansion = temp2;
}
if (firstExpansion == NULL && lastExpansion == NULL) {
ownBuffer->at(0) = firstValue;
ownBuffer->at(1) = lastValue;
result = ownBuffer;
}
else {
int32_t firstLength = firstExpansion==NULL? 1 : firstExpansion->size();
int32_t lastLength = lastExpansion==NULL? 1 : lastExpansion->size();
if (reorderBuffer == NULL) {
reorderBuffer = new VectorOfInt(firstLength+lastLength);
}
// reorderdBuffer gets reused for the life of this object.
// Since its internal buffer only grows, there is a danger
// that it will get really, really big, and never shrink. If
// this is actually happening, insert code here to check for
// the condition. Something along the lines of:
//! else if (reorderBuffer->size() >= 256 &&
//! (firstLength+lastLength) < 16) {
//! delete reorderBuffer;
//! reorderBuffer = new VectorOfInt(firstLength+lastLength);
//! }
// The specific numeric values need to be determined
// empirically. [aliu]
result = reorderBuffer;
if (firstExpansion == NULL) {
result->atPut(0, firstValue);
}
else {
// System.arraycopy(firstExpansion, 0, result, 0, firstLength);
*result = *firstExpansion;
}
if (lastExpansion == NULL) {
result->atPut(firstLength, lastValue);
}
else {
// System.arraycopy(lastExpansion, 0, result, firstLength, lastLength);
for (int32_t i=0; i<lastLength; ++i) {
result->atPut(firstLength + i, lastExpansion->at(i));
}
}
result->setSize(firstLength+lastLength);
}
return result;
}