scuffed-code/icu4c/source/common/rbbi.cpp

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/*
***************************************************************************
* Copyright (C) 1999-2004 International Business Machines Corporation *
* and others. All rights reserved. *
***************************************************************************
*/
//
// file: rbbi.c Contains the implementation of the rule based break iterator
// runtime engine and the API implementation for
// class RuleBasedBreakIterator
//
#include "unicode/utypes.h"
#if !UCONFIG_NO_BREAK_ITERATION
#include "unicode/rbbi.h"
#include "unicode/schriter.h"
#include "unicode/udata.h"
#include "unicode/uclean.h"
#include "rbbidata.h"
#include "rbbirb.h"
#include "cmemory.h"
#include "cstring.h"
#include "uassert.h"
U_NAMESPACE_BEGIN
static const int16_t START_STATE = 1; // The state number of the starting state
static const int16_t STOP_STATE = 0; // The state-transition value indicating "stop"
UOBJECT_DEFINE_RTTI_IMPLEMENTATION(RuleBasedBreakIterator)
//=======================================================================
// constructors
//=======================================================================
/**
* Constructs a RuleBasedBreakIterator that uses the already-created
* tables object that is passed in as a parameter.
*/
RuleBasedBreakIterator::RuleBasedBreakIterator(RBBIDataHeader* data, UErrorCode &status)
{
init();
fData = new RBBIDataWrapper(data, status); // status checked in constructor
if (U_FAILURE(status)) {return;}
if(fData == 0) {
status = U_MEMORY_ALLOCATION_ERROR;
return;
}
}
//-------------------------------------------------------------------------------
//
// Constructor from a UDataMemory handle to precompiled break rules
// stored in an ICU data file.
//
//-------------------------------------------------------------------------------
RuleBasedBreakIterator::RuleBasedBreakIterator(UDataMemory* udm, UErrorCode &status)
{
init();
fData = new RBBIDataWrapper(udm, status); // status checked in constructor
if (U_FAILURE(status)) {return;}
if(fData == 0) {
status = U_MEMORY_ALLOCATION_ERROR;
return;
}
}
//-------------------------------------------------------------------------------
//
// Constructor from a set of rules supplied as a string.
//
//-------------------------------------------------------------------------------
RuleBasedBreakIterator::RuleBasedBreakIterator( const UnicodeString &rules,
UParseError &parseError,
UErrorCode &status)
{
u_init(&status); // Just in case ICU is not yet initialized
init();
if (U_FAILURE(status)) {return;}
RuleBasedBreakIterator *bi = (RuleBasedBreakIterator *)
RBBIRuleBuilder::createRuleBasedBreakIterator(rules, parseError, status);
// Note: This is a bit awkward. The RBBI ruleBuilder has a factory method that
// creates and returns a complete RBBI. From here, in a constructor, we
// can't just return the object created by the builder factory, hence
// the assignment of the factory created object to "this".
if (U_SUCCESS(status)) {
*this = *bi;
delete bi;
}
}
//-------------------------------------------------------------------------------
//
// Default Constructor. Create an empty shell that can be set up later.
// Used when creating a RuleBasedBreakIterator from a set
// of rules.
//-------------------------------------------------------------------------------
RuleBasedBreakIterator::RuleBasedBreakIterator() {
init();
}
//-------------------------------------------------------------------------------
//
// Copy constructor. Will produce a break iterator with the same behavior,
// and which iterates over the same text, as the one passed in.
//
//-------------------------------------------------------------------------------
RuleBasedBreakIterator::RuleBasedBreakIterator(const RuleBasedBreakIterator& other)
: BreakIterator(other)
{
this->init();
*this = other;
}
/**
* Destructor
*/
RuleBasedBreakIterator::~RuleBasedBreakIterator() {
delete fText;
fText = NULL;
if (fData != NULL) {
fData->removeReference();
fData = NULL;
}
}
/**
* Assignment operator. Sets this iterator to have the same behavior,
* and iterate over the same text, as the one passed in.
*/
RuleBasedBreakIterator&
RuleBasedBreakIterator::operator=(const RuleBasedBreakIterator& that) {
if (this == &that) {
return *this;
}
delete fText;
fText = NULL;
if (that.fText != NULL) {
fText = that.fText->clone();
}
if (fData != NULL) {
fData->removeReference();
fData = NULL;
}
if (that.fData != NULL) {
fData = that.fData->addReference();
}
fTrace = that.fTrace;
return *this;
}
//-----------------------------------------------------------------------------
//
// init() Shared initialization routine. Used by all the constructors.
// Initializes all fields, leaving the object in a consistent state.
//
//-----------------------------------------------------------------------------
UBool RuleBasedBreakIterator::fTrace = FALSE;
void RuleBasedBreakIterator::init() {
fText = NULL;
fData = NULL;
fLastRuleStatusIndex = 0;
fLastStatusIndexValid = TRUE;
fDictionaryCharCount = 0;
#ifdef RBBI_DEBUG
static UBool debugInitDone = FALSE;
if (debugInitDone == FALSE) {
char *debugEnv = getenv("U_RBBIDEBUG");
if (debugEnv && uprv_strstr(debugEnv, "trace")) {
fTrace = TRUE;
}
debugInitDone = TRUE;
}
#endif
}
//-----------------------------------------------------------------------------
//
// clone - Returns a newly-constructed RuleBasedBreakIterator with the same
// behavior, and iterating over the same text, as this one.
// Virtual function: does the right thing with subclasses.
//
//-----------------------------------------------------------------------------
BreakIterator*
RuleBasedBreakIterator::clone(void) const {
return new RuleBasedBreakIterator(*this);
}
/**
* Equality operator. Returns TRUE if both BreakIterators are of the
* same class, have the same behavior, and iterate over the same text.
*/
UBool
RuleBasedBreakIterator::operator==(const BreakIterator& that) const {
UBool r = FALSE;
if (that.getDynamicClassID() != getDynamicClassID()) {
return r;
}
const RuleBasedBreakIterator& that2 = (const RuleBasedBreakIterator&) that;
if (fText == that2.fText ||
(fText != NULL && that2.fText != NULL && *that2.fText == *fText)) {
if (that2.fData == fData ||
(fData != NULL && that2.fData != NULL && *that2.fData == *fData)) {
r = TRUE;
}
}
return r;
}
/**
* Compute a hash code for this BreakIterator
* @return A hash code
*/
int32_t
RuleBasedBreakIterator::hashCode(void) const {
int32_t hash = 0;
if (fData != NULL) {
hash = fData->hashCode();
}
return hash;
}
/**
* Returns the description used to create this iterator
*/
const UnicodeString&
RuleBasedBreakIterator::getRules() const {
if (fData != NULL) {
return fData->getRuleSourceString();
} else {
static const UnicodeString *s;
if (s == NULL) {
// TODO: something more elegant here.
// perhaps API should return the string by value.
// Note: thread unsafe init & leak are semi-ok, better than
// what was before. Sould be cleaned up, though.
s = new UnicodeString;
}
return *s;
}
}
//=======================================================================
// BreakIterator overrides
//=======================================================================
/**
* Return a CharacterIterator over the text being analyzed. This version
* of this method returns the actual CharacterIterator we're using internally.
* Changing the state of this iterator can have undefined consequences. If
* you need to change it, clone it first.
* @return An iterator over the text being analyzed.
*/
const CharacterIterator&
RuleBasedBreakIterator::getText() const {
RuleBasedBreakIterator* nonConstThis = (RuleBasedBreakIterator*)this;
// The iterator is initialized pointing to no text at all, so if this
// function is called while we're in that state, we have to fudge an
// an iterator to return.
if (nonConstThis->fText == NULL) {
nonConstThis->fText = new StringCharacterIterator(UnicodeString());
}
return *nonConstThis->fText;
}
/**
* Set the iterator to analyze a new piece of text. This function resets
* the current iteration position to the beginning of the text.
* @param newText An iterator over the text to analyze.
*/
void
RuleBasedBreakIterator::adoptText(CharacterIterator* newText) {
reset();
delete fText;
fText = newText;
this->first();
}
/**
* Set the iterator to analyze a new piece of text. This function resets
* the current iteration position to the beginning of the text.
* @param newText An iterator over the text to analyze.
*/
void
RuleBasedBreakIterator::setText(const UnicodeString& newText) {
reset();
if (fText != NULL && fText->getDynamicClassID()
== StringCharacterIterator::getStaticClassID()) {
((StringCharacterIterator*)fText)->setText(newText);
}
else {
delete fText;
fText = new StringCharacterIterator(newText);
}
this->first();
}
/**
* Sets the current iteration position to the beginning of the text.
* (i.e., the CharacterIterator's starting offset).
* @return The offset of the beginning of the text.
*/
int32_t RuleBasedBreakIterator::first(void) {
reset();
fLastRuleStatusIndex = 0;
fLastStatusIndexValid = TRUE;
if (fText == NULL)
return BreakIterator::DONE;
fText->first();
return fText->getIndex();
}
/**
* Sets the current iteration position to the end of the text.
* (i.e., the CharacterIterator's ending offset).
* @return The text's past-the-end offset.
*/
int32_t RuleBasedBreakIterator::last(void) {
reset();
if (fText == NULL) {
fLastRuleStatusIndex = 0;
fLastStatusIndexValid = TRUE;
return BreakIterator::DONE;
}
// I'm not sure why, but t.last() returns the offset of the last character,
// rather than the past-the-end offset
//
// (It's so a loop like for(p=it.last(); p!=DONE; p=it.previous()) ...
// will work correctly.)
fLastStatusIndexValid = FALSE;
int32_t pos = fText->endIndex();
fText->setIndex(pos);
return pos;
}
/**
* Advances the iterator either forward or backward the specified number of steps.
* Negative values move backward, and positive values move forward. This is
* equivalent to repeatedly calling next() or previous().
* @param n The number of steps to move. The sign indicates the direction
* (negative is backwards, and positive is forwards).
* @return The character offset of the boundary position n boundaries away from
* the current one.
*/
int32_t RuleBasedBreakIterator::next(int32_t n) {
int32_t result = current();
while (n > 0) {
result = handleNext();
--n;
}
while (n < 0) {
result = previous();
++n;
}
return result;
}
/**
* Advances the iterator to the next boundary position.
* @return The position of the first boundary after this one.
*/
int32_t RuleBasedBreakIterator::next(void) {
return handleNext();
}
/**
* Advances the iterator backwards, to the last boundary preceding this one.
* @return The position of the last boundary position preceding this one.
*/
int32_t RuleBasedBreakIterator::previous(void) {
// if we're already sitting at the beginning of the text, return DONE
if (fText == NULL || current() == fText->startIndex()) {
fLastRuleStatusIndex = 0;
fLastStatusIndexValid = TRUE;
return BreakIterator::DONE;
}
if (fData->fSafeRevTable != NULL || fData->fSafeFwdTable != NULL) {
return handlePrevious(fData->fReverseTable);
}
// old rule syntax
// set things up. handlePrevious() will back us up to some valid
// break position before the current position (we back our internal
// iterator up one step to prevent handlePrevious() from returning
// the current position), but not necessarily the last one before
// where we started
int32_t start = current();
fText->previous32();
int32_t lastResult = handlePrevious();
int32_t result = lastResult;
int32_t lastTag = 0;
UBool breakTagValid = FALSE;
// iterate forward from the known break position until we pass our
// starting point. The last break position before the starting
// point is our return value
for (;;) {
result = handleNext();
if (result == BreakIterator::DONE || result >= start) {
break;
}
lastResult = result;
lastTag = fLastRuleStatusIndex;
breakTagValid = TRUE;
}
// fLastBreakTag wants to have the value for section of text preceding
// the result position that we are to return (in lastResult.) If
// the backwards rules overshot and the above loop had to do two or more
// handleNext()s to move up to the desired return position, we will have a valid
// tag value. But, if handlePrevious() took us to exactly the correct result positon,
// we wont have a tag value for that position, which is only set by handleNext().
// set the current iteration position to be the last break position
// before where we started, and then return that value
fText->setIndex(lastResult);
fLastRuleStatusIndex = lastTag; // for use by getRuleStatus()
fLastStatusIndexValid = breakTagValid;
return lastResult;
}
/**
* Sets the iterator to refer to the first boundary position following
* the specified position.
* @offset The position from which to begin searching for a break position.
* @return The position of the first break after the current position.
*/
int32_t RuleBasedBreakIterator::following(int32_t offset) {
// if the offset passed in is already past the end of the text,
// just return DONE; if it's before the beginning, return the
// text's starting offset
fLastRuleStatusIndex = 0;
fLastStatusIndexValid = TRUE;
if (fText == NULL || offset >= fText->endIndex()) {
last();
return next();
}
else if (offset < fText->startIndex()) {
return first();
}
// otherwise, set our internal iteration position (temporarily)
// to the position passed in. If this is the _beginning_ position,
// then we can just use next() to get our return value
int32_t result = 0;
if (fData->fSafeRevTable != NULL) {
// new rule syntax
/// todo synwee
fText->setIndex(offset);
// move forward one codepoint to prepare for moving back to a
// safe point.
// this handles offset being between a supplementary character
fText->next32();
// handlePrevious will move most of the time to < 1 boundary away
handlePrevious(fData->fSafeRevTable);
int32_t result = next();
while (result <= offset) {
result = next();
}
return result;
}
if (fData->fSafeFwdTable != NULL) {
// backup plan if forward safe table is not available
fText->setIndex(offset);
fText->previous32();
// handle next will give result >= offset
handleNext(fData->fSafeFwdTable);
// previous will give result 0 or 1 boundary away from offset,
// most of the time
// we have to
int32_t oldresult = previous();
while (oldresult > offset) {
int32_t result = previous();
if (result <= offset) {
return oldresult;
}
oldresult = result;
}
int32_t result = next();
if (result <= offset) {
return next();
}
return result;
}
// otherwise, we have to sync up first. Use handlePrevious() to back
// us up to a known break position before the specified position (if
// we can determine that the specified position is a break position,
// we don't back up at all). This may or may not be the last break
// position at or before our starting position. Advance forward
// from here until we've passed the starting position. The position
// we stop on will be the first break position after the specified one.
// old rule syntax
fText->setIndex(offset);
if (offset == fText->startIndex()) {
return handleNext();
}
result = previous();
while (result != BreakIterator::DONE && result <= offset) {
result = next();
}
return result;
}
/**
* Sets the iterator to refer to the last boundary position before the
* specified position.
* @offset The position to begin searching for a break from.
* @return The position of the last boundary before the starting position.
*/
int32_t RuleBasedBreakIterator::preceding(int32_t offset) {
// if the offset passed in is already past the end of the text,
// just return DONE; if it's before the beginning, return the
// text's starting offset
if (fText == NULL || offset > fText->endIndex()) {
// return BreakIterator::DONE;
return last();
}
else if (offset < fText->startIndex()) {
return first();
}
// if we start by updating the current iteration position to the
// position specified by the caller, we can just use previous()
// to carry out this operation
if (fData->fSafeFwdTable != NULL) {
/// todo synwee
// new rule syntax
fText->setIndex(offset);
// move backwards one codepoint to prepare for moving forwards to a
// safe point.
// this handles offset being between a supplementary character
// TODO: would it be better to just check for being in the middle of a surrogate pair,
// rather than adjusting the position unconditionally?
// (Change would interact with safe rules.)
fText->previous32();
handleNext(fData->fSafeFwdTable);
int32_t result = fText->getIndex();
while (result >= offset) {
result = previous();
}
return result;
}
if (fData->fSafeRevTable != NULL) {
// backup plan if forward safe table is not available
fText->setIndex(offset);
fText->next32();
// handle previous will give result <= offset
handlePrevious(fData->fSafeRevTable);
// next will give result 0 or 1 boundary away from offset,
// most of the time
// we have to
int32_t oldresult = next();
while (oldresult < offset) {
int32_t result = next();
if (result >= offset) {
return oldresult;
}
oldresult = result;
}
int32_t result = previous();
if (result >= offset) {
return previous();
}
return result;
}
// old rule syntax
fText->setIndex(offset);
return previous();
}
/**
* Returns true if the specfied position is a boundary position. As a side
* effect, leaves the iterator pointing to the first boundary position at
* or after "offset".
* @param offset the offset to check.
* @return True if "offset" is a boundary position.
*/
UBool RuleBasedBreakIterator::isBoundary(int32_t offset) {
// the beginning index of the iterator is always a boundary position by definition
if (fText == NULL || offset == fText->startIndex()) {
first(); // For side effects on current position, tag values.
return TRUE;
}
if (offset == fText->endIndex()) {
last(); // For side effects on current position, tag values.
return TRUE;
}
// out-of-range indexes are never boundary positions
if (offset < fText->startIndex()) {
first(); // For side effects on current position, tag values.
return FALSE;
}
if (offset > fText->endIndex()) {
last(); // For side effects on current position, tag values.
return FALSE;
}
// otherwise, we can use following() on the position before the specified
// one and return true if the position we get back is the one the user
// specified
return following(offset - 1) == offset;
}
/**
* Returns the current iteration position.
* @return The current iteration position.
*/
int32_t RuleBasedBreakIterator::current(void) const {
return (fText != NULL) ? fText->getIndex() : BreakIterator::DONE;
}
//=======================================================================
// implementation
//=======================================================================
//-----------------------------------------------------------------------------------
//
// handleNext()
// This method is the actual implementation of the next() method. All iteration
// vectors through here. This method initializes the state machine to state 1
// and advances through the text character by character until we reach the end
// of the text or the state machine transitions to state 0. We update our return
// value every time the state machine passes through an accepting state.
//
//-----------------------------------------------------------------------------------
int32_t RuleBasedBreakIterator::handleNext() {
return handleNext(fData->fForwardTable);
}
int32_t RuleBasedBreakIterator::handleNext(const RBBIStateTable *statetable) {
if (fTrace) {
RBBIDebugPrintf("Handle Next pos char state category \n");
}
// No matter what, handleNext alway correctly sets the break tag value.
fLastStatusIndexValid = TRUE;
// if we're already at the end of the text, return DONE.
if (fText == NULL || fData == NULL || fText->hasNext() == FALSE) {
fLastRuleStatusIndex = 0;
return BreakIterator::DONE;
}
int32_t initialPosition = fText->getIndex();
int32_t result = initialPosition;
int32_t lookaheadResult = 0;
// Initialize the state machine. Begin in state 1
int32_t state = START_STATE;
int16_t category;
UChar32 c = fText->current32();
RBBIStateTableRow *row;
int32_t lookaheadStatus = 0;
int32_t lookaheadTagIdx = 0;
fLastRuleStatusIndex = 0;
row = (RBBIStateTableRow *) // Point to starting row of state table.
(statetable->fTableData + (statetable->fRowLen * state));
// Character Category fetch for starting character.
// See comments on character category code within loop, below.
UTRIE_GET16(&fData->fTrie, c, category);
if ((category & 0x4000) != 0) {
fDictionaryCharCount++;
category &= ~0x4000;
}
// loop until we reach the end of the text or transition to state 0
for (;;) {
if (c == CharacterIterator::DONE && fText->hasNext()==FALSE) {
// Reached end of input string.
// Note: CharacterIterator::DONE is 0xffff, which is also a legal
// character value. Check for DONE first, because it's quicker,
// but also need to check fText->hasNext() to be certain.
if (lookaheadResult > result) {
// We ran off the end of the string with a pending look-ahead match.
// Treat this as if the look-ahead condition had been met, and return
// the match at the / position from the look-ahead rule.
result = lookaheadResult;
fLastRuleStatusIndex = lookaheadTagIdx;
lookaheadStatus = 0;
} else if (result == initialPosition) {
// Ran off end, no match found.
// move forward one
fText->setIndex(initialPosition);
fText->next32();
fText->getIndex();
}
break;
}
// look up the current character's character category, which tells us
// which column in the state table to look at.
// Note: the 16 in UTRIE_GET16 refers to the size of the data being returned,
// not the size of the character going in, which is a UChar32.
//
UTRIE_GET16(&fData->fTrie, c, category);
// Check the dictionary bit in the character's category.
// Counter is only used by dictionary based iterators (subclasses).
// Chars that need to be handled by a dictionary have a flag bit set
// in their category values.
//
if ((category & 0x4000) != 0) {
fDictionaryCharCount++;
// And off the dictionary flag bit.
category &= ~0x4000;
}
if (fTrace) {
RBBIDebugPrintf(" %4d ", fText->getIndex());
if (0x20<=c && c<0x7f) {
RBBIDebugPrintf("\"%c\" ", c);
} else {
RBBIDebugPrintf("%5x ", c);
}
RBBIDebugPrintf("%3d %3d\n", state, category);
}
// look up a state transition in the state table
state = row->fNextState[category];
row = (RBBIStateTableRow *)
(statetable->fTableData + (statetable->fRowLen * state));
// Get the next character. Doing it here positions the iterator
// to the correct position for recording matches in the code that
// follows.
c = fText->next32();
if (row->fAccepting == -1) {
// Match found, common case, could have lookahead so we move on to check it
result = fText->getIndex();
/// added
fLastRuleStatusIndex = row->fTagIdx; // Remember the break status (tag) values.
}
if (row->fLookAhead != 0) {
if (lookaheadStatus != 0
&& row->fAccepting == lookaheadStatus) {
// Lookahead match is completed. Set the result accordingly, but only
// if no other rule has matched further in the mean time.
result = lookaheadResult;
fLastRuleStatusIndex = lookaheadTagIdx;
lookaheadStatus = 0;
/// i think we have to back up to read the lookahead character again
/// fText->setIndex(lookaheadResult);
/// TODO: this is a simple hack since reverse rules only have simple
/// lookahead rules that we can definitely break out from.
/// we need to make the lookahead rules not chain eventually.
/// return result;
/// this is going to be the longest match again
goto continueOn;
}
int32_t r = fText->getIndex();
lookaheadResult = r;
lookaheadStatus = row->fLookAhead;
lookaheadTagIdx = row->fTagIdx;
goto continueOn;
}
if (row->fAccepting == 0) {
// No match, nothing of interest happening, common case.
goto continueOn;
}
lookaheadStatus = 0; // clear out any pending look-ahead matches.
continueOn:
if (state == STOP_STATE) {
// This is the normal exit from the lookup state machine.
// We have advanced through the string until it is certain that no
// longer match is possible, no matter what characters follow.
break;
}
}
// The state machine is done. Check whether it found a match...
// If the iterator failed to advance in the match engine, force it ahead by one.
// (This really indicates a defect in the break rules. They should always match
// at least one character.)
if (result == initialPosition) {
result = fText->setIndex(initialPosition);
fText ->next32();
result = fText->getIndex();
}
// Leave the iterator at our result position.
fText->setIndex(result);
if (fTrace) {
RBBIDebugPrintf("result = %d\n\n", result);
}
return result;
}
//----------------------------------------------------------------
//
// handlePrevious(void) This is the variant used with old style rules
// (Overshoot to a safe point, then move forward)
//
//----------------------------------------------------------------
int32_t RuleBasedBreakIterator::handlePrevious(void) {
if (fText == NULL || fData == NULL) {
return 0;
}
if (fData->fReverseTable == NULL) {
return fText->setToStart();
}
int32_t state = START_STATE;
int32_t category;
int32_t lastCategory = 0;
int32_t result = fText->getIndex();
int32_t lookaheadStatus = 0;
int32_t lookaheadResult = 0;
int32_t lookaheadTagIdx = 0;
UChar32 c = fText->current32();
RBBIStateTableRow *row;
row = (RBBIStateTableRow *)
(this->fData->fReverseTable->fTableData + (state * fData->fReverseTable->fRowLen));
UTRIE_GET16(&fData->fTrie, c, category);
if ((category & 0x4000) != 0) {
fDictionaryCharCount++;
category &= ~0x4000;
}
if (fTrace) {
RBBIDebugPrintf("Handle Prev pos char state category \n");
}
// loop until we reach the beginning of the text or transition to state 0
for (;;) {
if (c == CharacterIterator::DONE && fText->hasPrevious()==FALSE) {
break;
}
// save the last character's category and look up the current
// character's category
lastCategory = category;
UTRIE_GET16(&fData->fTrie, c, category);
// Check the dictionary bit in the character's category.
// Counter is only used by dictionary based iterators.
//
if ((category & 0x4000) != 0) {
fDictionaryCharCount++;
category &= ~0x4000;
}
if (fTrace) {
RBBIDebugPrintf(" %4d ", fText->getIndex());
if (0x20<=c && c<0x7f) {
RBBIDebugPrintf("\"%c\" ", c);
} else {
RBBIDebugPrintf("%5x ", c);
}
RBBIDebugPrintf("%3d %3d\n", state, category);
}
// look up a state transition in the backwards state table
state = row->fNextState[category];
row = (RBBIStateTableRow *)
(this->fData->fReverseTable->fTableData + (state * fData->fReverseTable->fRowLen));
if (row->fAccepting == 0 && row->fLookAhead == 0) {
// No match, nothing of interest happening, common case.
goto continueOn;
}
if (row->fAccepting == -1) {
// Match found, common case, no lookahead involved.
result = fText->getIndex();
lookaheadStatus = 0; // clear out any pending look-ahead matches.
goto continueOn;
}
if (row->fAccepting == 0 && row->fLookAhead != 0) {
// Lookahead match point. Remember it, but only if no other rule
// has unconditionally matched to this point.
// TODO: handle case where there's a pending match from a different rule
// where lookaheadStatus != 0 && lookaheadStatus != row->fLookAhead.
int32_t r = fText->getIndex();
if (r > result) {
lookaheadResult = r;
lookaheadStatus = row->fLookAhead;
lookaheadTagIdx = row->fTagIdx;
}
goto continueOn;
}
if (row->fAccepting != 0 && row->fLookAhead != 0) {
// Lookahead match is completed. Set the result accordingly, but only
// if no other rule has matched further in the mean time.
if (lookaheadResult > result) {
U_ASSERT(row->fAccepting == lookaheadStatus); // TODO: handle this case
// of overlapping lookahead matches.
result = lookaheadResult;
fLastRuleStatusIndex = lookaheadTagIdx;
lookaheadStatus = 0;
}
goto continueOn;
}
continueOn:
if (state == STOP_STATE) {
break;
}
// then advance one character backwards
c = fText->previous32();
}
// Note: the result postion isn't what is returned to the user by previous(),
// but where the implementation of previous() turns around and
// starts iterating forward again.
if (c == CharacterIterator::DONE && fText->hasPrevious()==FALSE) {
result = fText->startIndex();
}
fText->setIndex(result);
return result;
}
//-----------------------------------------------------------------------------------
//
// handlePrevious()
//
// This method backs the iterator back up to a "safe position" in the text.
// This is a position that we know, without any context, may be any position
// not more than 2 breaks away. Occasionally, the position may be less than
// one break away.
// The various calling methods then iterate forward from this safe position to
// the appropriate position to return.
//
// The logic of this function is very similar to handleNext(), above.
//
//-----------------------------------------------------------------------------------
int32_t RuleBasedBreakIterator::handlePrevious(const RBBIStateTable *statetable) {
if (fText == NULL || statetable == NULL) {
return 0;
}
// break tag is no longer valid after icu switched to exact backwards
// positioning.
fLastStatusIndexValid = FALSE;
if (statetable == NULL) {
return fText->setToStart();
}
int32_t state = START_STATE;
int32_t category;
int32_t lastCategory = 0;
UBool hasPassedStartText = !fText->hasPrevious();
UChar32 c = fText->previous32();
// previous character
int32_t result = fText->getIndex();
int32_t lookaheadStatus = 0;
int32_t lookaheadResult = 0;
int32_t lookaheadTagIdx = 0;
UBool lookAheadHardBreak = (statetable->fFlags & RBBI_LOOKAHEAD_HARD_BREAK) != 0;
RBBIStateTableRow *row;
row = (RBBIStateTableRow *)
(statetable->fTableData + (state * statetable->fRowLen));
UTRIE_GET16(&fData->fTrie, c, category);
if ((category & 0x4000) != 0) {
fDictionaryCharCount++;
category &= ~0x4000;
}
if (fTrace) {
RBBIDebugPrintf("Handle Prev pos char state category \n");
}
// loop until we reach the beginning of the text or transition to state 0
for (;;) {
// if (c == CharacterIterator::DONE && fText->hasPrevious()==FALSE) {
if (hasPassedStartText) {
// if we have already considered the start of the text
if (row->fLookAhead != 0 && lookaheadResult == 0) {
result = 0;
}
break;
}
// save the last character's category and look up the current
// character's category
lastCategory = category;
UTRIE_GET16(&fData->fTrie, c, category);
// Check the dictionary bit in the character's category.
// Counter is only used by dictionary based iterators.
//
if ((category & 0x4000) != 0) {
fDictionaryCharCount++;
category &= ~0x4000;
}
if (fTrace) {
RBBIDebugPrintf(" %4d ", fText->getIndex());
if (0x20<=c && c<0x7f) {
RBBIDebugPrintf("\"%c\" ", c);
} else {
RBBIDebugPrintf("%5x ", c);
}
RBBIDebugPrintf("%3d %3d\n", state, category);
}
// look up a state transition in the backwards state table
state = row->fNextState[category];
row = (RBBIStateTableRow *)
(statetable->fTableData + (state * statetable->fRowLen));
if (row->fAccepting == -1) {
// Match found, common case, could have lookahead so we move on to check it
result = fText->getIndex();
/// added
fLastRuleStatusIndex = row->fTagIdx; // Remember the break status (tag) value.
}
if (row->fLookAhead != 0) {
if (lookaheadStatus != 0
&& row->fAccepting == lookaheadStatus) {
// Lookahead match is completed. Set the result accordingly, but only
// if no other rule has matched further in the mean time.
result = lookaheadResult;
fLastRuleStatusIndex = lookaheadTagIdx;
lookaheadStatus = 0;
/// i think we have to back up to read the lookahead character again
/// fText->setIndex(lookaheadResult);
/// TODO: this is a simple hack since reverse rules only have simple
/// lookahead rules that we can definitely break out from.
/// we need to make the lookahead rules not chain eventually.
/// return result;
/// this is going to be the longest match again
/// syn wee todo hard coded for line breaks stuff
/// needs to provide a tag in rules to ensure a stop.
if (lookAheadHardBreak) {
fText->setIndex(result);
return result;
}
category = lastCategory;
fText->setIndex(result);
goto continueOn;
}
int32_t r = fText->getIndex();
lookaheadResult = r;
lookaheadStatus = row->fLookAhead;
fLastRuleStatusIndex = row->fTagIdx;
goto continueOn;
}
// not lookahead
if (row->fAccepting == 0) {
// No match, nothing of interest happening, common case.
goto continueOn;
}
lookaheadStatus = 0; // clear out any pending look-ahead matches.
continueOn:
if (state == STOP_STATE) {
break;
}
// then advance one character backwards
hasPassedStartText = !fText->hasPrevious();
c = fText->previous32();
}
// Note: the result postion isn't what is returned to the user by previous(),
// but where the implementation of previous() turns around and
// starts iterating forward again.
fText->setIndex(result);
return result;
}
void
RuleBasedBreakIterator::reset()
{
// Base-class version of this function is a no-op.
// Subclasses may override with their own reset behavior.
}
//-------------------------------------------------------------------------------
//
// getRuleStatus() Return the break rule tag associated with the current
// iterator position. If the iterator arrived at its current
// position by iterating forwards, the value will have been
// cached by the handleNext() function.
//
// If no cached status value is available, the status is
// found by doing a previous() followed by a next(), which
// leaves the iterator where it started, and computes the
// status while doing the next().
//
//-------------------------------------------------------------------------------
void RuleBasedBreakIterator::makeRuleStatusValid() {
if (fLastStatusIndexValid == FALSE) {
// No cached status is available.
if (fText == NULL || current() == fText->startIndex()) {
// At start of text, or there is no text. Status is always zero.
fLastRuleStatusIndex = 0;
fLastStatusIndexValid = TRUE;
} else {
// Not at start of text. Find status the tedious way.
int32_t pa = current();
previous();
int32_t pb = next();
if (pa != pb) {
// note: the if (pa != pb) test is here only to eliminate warnings for
// unused local variables on gcc. Logically, it isn't needed.
U_ASSERT(pa == pb);
}
}
}
U_ASSERT(fLastStatusIndexValid == TRUE);
U_ASSERT(fLastRuleStatusIndex >= 0 && fLastRuleStatusIndex < fData->fStatusMaxIdx);
}
int32_t RuleBasedBreakIterator::getRuleStatus() const {
RuleBasedBreakIterator *nonConstThis = (RuleBasedBreakIterator *)this;
nonConstThis->makeRuleStatusValid();
// fLastRuleStatusIndex indexes to the start of the appropriate status record
// (the number of status values.)
// This function returns the last (largest) of the array of status values.
int32_t idx = fLastRuleStatusIndex + fData->fRuleStatusTable[fLastRuleStatusIndex];
int32_t tagVal = fData->fRuleStatusTable[idx];
return tagVal;
}
int32_t RuleBasedBreakIterator::getRuleStatusVec(
int32_t *fillInVec, int32_t capacity, UErrorCode &status)
{
if (U_FAILURE(status)) {
return 0;
}
RuleBasedBreakIterator *nonConstThis = (RuleBasedBreakIterator *)this;
nonConstThis->makeRuleStatusValid();
int32_t numVals = fData->fRuleStatusTable[fLastRuleStatusIndex];
int32_t numValsToCopy = numVals;
if (numVals > capacity) {
status = U_BUFFER_OVERFLOW_ERROR;
numValsToCopy = capacity;
}
int i;
for (i=0; i<numValsToCopy; i++) {
fillInVec[i] = fData->fRuleStatusTable[fLastRuleStatusIndex + i + 1];
}
return numVals;
}
//-------------------------------------------------------------------------------
//
// getBinaryRules Access to the compiled form of the rules,
// for use by build system tools that save the data
// for standard iterator types.
//
//-------------------------------------------------------------------------------
const uint8_t *RuleBasedBreakIterator::getBinaryRules(uint32_t &length) {
const uint8_t *retPtr = NULL;
length = 0;
if (fData != NULL) {
retPtr = (const uint8_t *)fData->fHeader;
length = fData->fHeader->fLength;
}
return retPtr;
}
//-------------------------------------------------------------------------------
//
// BufferClone TODO: In my (Andy) opinion, this function should be deprecated.
// Saving one heap allocation isn't worth the trouble.
// Cloning shouldn't be done in tight loops, and
// making the clone copy involves other heap operations anyway.
// And the application code for correctly dealing with buffer
// size problems and the eventual object destruction is ugly.
//
//-------------------------------------------------------------------------------
BreakIterator * RuleBasedBreakIterator::createBufferClone(void *stackBuffer,
int32_t &bufferSize,
UErrorCode &status)
{
if (U_FAILURE(status)){
return NULL;
}
//
// If user buffer size is zero this is a preflight operation to
// obtain the needed buffer size, allowing for worst case misalignment.
//
if (bufferSize == 0) {
bufferSize = sizeof(RuleBasedBreakIterator) + U_ALIGNMENT_OFFSET_UP(0);
return NULL;
}
//
// Check the alignment and size of the user supplied buffer.
// Allocate heap memory if the user supplied memory is insufficient.
//
char *buf = (char *)stackBuffer;
uint32_t s = bufferSize;
if (stackBuffer == NULL) {
s = 0; // Ignore size, force allocation if user didn't give us a buffer.
}
if (U_ALIGNMENT_OFFSET(stackBuffer) != 0) {
uint32_t offsetUp = (uint32_t)U_ALIGNMENT_OFFSET_UP(buf);
s -= offsetUp;
buf += offsetUp;
}
if (s < sizeof(RuleBasedBreakIterator)) {
buf = (char *) new RuleBasedBreakIterator;
if (buf == 0) {
status = U_MEMORY_ALLOCATION_ERROR;
return NULL;
}
status = U_SAFECLONE_ALLOCATED_WARNING;
}
//
// Clone the object.
// TODO: using an overloaded operator new to directly initialize the
// copy in the user's buffer would be better, but it doesn't seem
// to get along with namespaces. Investigate why.
//
// The memcpy is only safe with an empty (default constructed)
// break iterator. Use on others can screw up reference counts
// to data. memcpy-ing objects is not really a good idea...
//
RuleBasedBreakIterator localIter; // Empty break iterator, source for memcpy
RuleBasedBreakIterator *clone = (RuleBasedBreakIterator *)buf;
uprv_memcpy(clone, &localIter, sizeof(RuleBasedBreakIterator)); // clone = empty, but initialized, iterator.
*clone = *this; // clone = the real one we want.
if (status != U_SAFECLONE_ALLOCATED_WARNING) {
clone->fBufferClone = TRUE;
}
return clone;
}
//-------------------------------------------------------------------------------
//
// isDictionaryChar Return true if the category lookup for this char
// indicates that it is in the set of dictionary lookup
// chars.
//
// This function is intended for use by dictionary based
// break iterators.
//
//-------------------------------------------------------------------------------
UBool RuleBasedBreakIterator::isDictionaryChar(UChar32 c) {
if (fData == NULL) {
return FALSE;
}
uint16_t category;
UTRIE_GET16(&fData->fTrie, c, category);
return (category & 0x4000) != 0;
}
U_NAMESPACE_END
#endif /* #if !UCONFIG_NO_BREAK_ITERATION */