The Tor Browser: comparison intl/icu/source/common/unisetspan.cpp

--1:000000000000
+:e641256aeef4
+/*
+******************************************************************************
+*
+*   Copyright (C) 2007-2012, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+*
+******************************************************************************
+*   file name:  unisetspan.cpp
+*   encoding:   US-ASCII
+*   tab size:   8 (not used)
+*   indentation:4
+*
+*   created on: 2007mar01
+*   created by: Markus W. Scherer
+*/
+#include "unicode/utypes.h"
+#include "unicode/uniset.h"
+#include "unicode/ustring.h"
+#include "unicode/utf8.h"
+#include "unicode/utf16.h"
+#include "cmemory.h"
+#include "uvector.h"
+#include "unisetspan.h"
+U_NAMESPACE_BEGIN
+/*
+* List of offsets from the current position from where to try matching
+* a code point or a string.
+* Store offsets rather than indexes to simplify the code and use the same list
+* for both increments (in span()) and decrements (in spanBack()).
+*
+* Assumption: The maximum offset is limited, and the offsets that are stored
+* at any one time are relatively dense, that is, there are normally no gaps of
+* hundreds or thousands of offset values.
+*
+* The implementation uses a circular buffer of byte flags,
+* each indicating whether the corresponding offset is in the list.
+* This avoids inserting into a sorted list of offsets (or absolute indexes) and
+* physically moving part of the list.
+*
+* Note: In principle, the caller should setMaxLength() to the maximum of the
+* max string length and U16_LENGTH/U8_LENGTH to account for
+* "long" single code points.
+* However, this implementation uses at least a staticList with more than
+* U8_LENGTH entries anyway.
+*
+* Note: If maxLength were guaranteed to be no more than 32 or 64,
+* the list could be stored as bit flags in a single integer.
+* Rather than handling a circular buffer with a start list index,
+* the integer would simply be shifted when lower offsets are removed.
+* UnicodeSet does not have a limit on the lengths of strings.
+*/
+class OffsetList {  // Only ever stack-allocated, does not need to inherit UMemory.
+public:
+OffsetList() : list(staticList), capacity(0), length(0), start(0) {}
+~OffsetList() {
+if(list!=staticList) {
+uprv_free(list);
+}
+}
+// Call exactly once if the list is to be used.
+void setMaxLength(int32_t maxLength) {
+if(maxLength<=(int32_t)sizeof(staticList)) {
+capacity=(int32_t)sizeof(staticList);
+} else {
+UBool *l=(UBool *)uprv_malloc(maxLength);
+if(l!=NULL) {
+list=l;
+capacity=maxLength;
+}
+}
+uprv_memset(list, 0, capacity);
+}
+void clear() {
+uprv_memset(list, 0, capacity);
+start=length=0;
+}
+UBool isEmpty() const {
+return (UBool)(length==0);
+}
+// Reduce all stored offsets by delta, used when the current position
+// moves by delta.
+// There must not be any offsets lower than delta.
+// If there is an offset equal to delta, it is removed.
+// delta=[1..maxLength]
+void shift(int32_t delta) {
+int32_t i=start+delta;
+if(i>=capacity) {
+i-=capacity;
+}
+if(list[i]) {
+list[i]=FALSE;
+--length;
+}
+start=i;
+}
+// Add an offset. The list must not contain it yet.
+// offset=[1..maxLength]
+void addOffset(int32_t offset) {
+int32_t i=start+offset;
+if(i>=capacity) {
+i-=capacity;
+}
+list[i]=TRUE;
+++length;
+}
+// offset=[1..maxLength]
+UBool containsOffset(int32_t offset) const {
+int32_t i=start+offset;
+if(i>=capacity) {
+i-=capacity;
+}
+return list[i];
+}
+// Find the lowest stored offset from a non-empty list, remove it,
+// and reduce all other offsets by this minimum.
+// Returns [1..maxLength].
+int32_t popMinimum() {
+// Look for the next offset in list[start+1..capacity-1].
+int32_t i=start, result;
+while(++i<capacity) {
+if(list[i]) {
+list[i]=FALSE;
+--length;
+result=i-start;
+start=i;
+return result;
+}
+}
+// i==capacity
+// Wrap around and look for the next offset in list[0..start].
+// Since the list is not empty, there will be one.
+result=capacity-start;
+i=0;
+while(!list[i]) {
+++i;
+}
+list[i]=FALSE;
+--length;
+start=i;
+return result+=i;
+}
+private:
+UBool *list;
+int32_t capacity;
+int32_t length;
+int32_t start;
+UBool staticList[16];
+};
+// Get the number of UTF-8 bytes for a UTF-16 (sub)string.
+static int32_t
+getUTF8Length(const UChar *s, int32_t length) {
+UErrorCode errorCode=U_ZERO_ERROR;
+int32_t length8=0;
+u_strToUTF8(NULL, 0, &length8, s, length, &errorCode);
+if(U_SUCCESS(errorCode) || errorCode==U_BUFFER_OVERFLOW_ERROR) {
+return length8;
+} else {
+// The string contains an unpaired surrogate.
+// Ignore this string.
+return 0;
+}
+}
+// Append the UTF-8 version of the string to t and return the appended UTF-8 length.
+static int32_t
+appendUTF8(const UChar *s, int32_t length, uint8_t *t, int32_t capacity) {
+UErrorCode errorCode=U_ZERO_ERROR;
+int32_t length8=0;
+u_strToUTF8((char *)t, capacity, &length8, s, length, &errorCode);
+if(U_SUCCESS(errorCode)) {
+return length8;
+} else {
+// The string contains an unpaired surrogate.
+// Ignore this string.
+return 0;
+}
+}
+static inline uint8_t
+makeSpanLengthByte(int32_t spanLength) {
+// 0xfe==UnicodeSetStringSpan::LONG_SPAN
+return spanLength<0xfe ? (uint8_t)spanLength : (uint8_t)0xfe;
+}
+// Construct for all variants of span(), or only for any one variant.
+// Initialize as little as possible, for single use.
+UnicodeSetStringSpan::UnicodeSetStringSpan(const UnicodeSet &set,
+const UVector &setStrings,
+uint32_t which)
+: spanSet(0, 0x10ffff), pSpanNotSet(NULL), strings(setStrings),
+utf8Lengths(NULL), spanLengths(NULL), utf8(NULL),
+utf8Length(0),
+maxLength16(0), maxLength8(0),
+all((UBool)(which==ALL)) {
+spanSet.retainAll(set);
+if(which&NOT_CONTAINED) {
+// Default to the same sets.
+// addToSpanNotSet() will create a separate set if necessary.
+pSpanNotSet=&spanSet;
+}
+// Determine if the strings even need to be taken into account at all for span() etc.
+// If any string is relevant, then all strings need to be used for
+// span(longest match) but only the relevant ones for span(while contained).
+// TODO: Possible optimization: Distinguish CONTAINED vs. LONGEST_MATCH
+//   and do not store UTF-8 strings if !thisRelevant and CONTAINED.
+//   (Only store irrelevant UTF-8 strings for LONGEST_MATCH where they are relevant after all.)
+// Also count the lengths of the UTF-8 versions of the strings for memory allocation.
+int32_t stringsLength=strings.size();
+int32_t i, spanLength;
+UBool someRelevant=FALSE;
+for(i=0; i<stringsLength; ++i) {
+const UnicodeString &string=*(const UnicodeString *)strings.elementAt(i);
+const UChar *s16=string.getBuffer();
+int32_t length16=string.length();
+UBool thisRelevant;
+spanLength=spanSet.span(s16, length16, USET_SPAN_CONTAINED);
+if(spanLength<length16) {  // Relevant string.
+someRelevant=thisRelevant=TRUE;
+} else {
+thisRelevant=FALSE;
+}
+if((which&UTF16) && length16>maxLength16) {
+maxLength16=length16;
+}
+if((which&UTF8) && (thisRelevant || (which&CONTAINED))) {
+int32_t length8=getUTF8Length(s16, length16);
+utf8Length+=length8;
+if(length8>maxLength8) {
+maxLength8=length8;
+}
+}
+}
+if(!someRelevant) {
+maxLength16=maxLength8=0;
+return;
+}
+// Freeze after checking for the need to use strings at all because freezing
+// a set takes some time and memory which are wasted if there are no relevant strings.
+if(all) {
+spanSet.freeze();
+}
+uint8_t *spanBackLengths;
+uint8_t *spanUTF8Lengths;
+uint8_t *spanBackUTF8Lengths;
+// Allocate a block of meta data.
+int32_t allocSize;
+if(all) {
+// UTF-8 lengths, 4 sets of span lengths, UTF-8 strings.
+allocSize=stringsLength*(4+1+1+1+1)+utf8Length;
+} else {
+allocSize=stringsLength;  // One set of span lengths.
+if(which&UTF8) {
+// UTF-8 lengths and UTF-8 strings.
+allocSize+=stringsLength*4+utf8Length;
+}
+}
+if(allocSize<=(int32_t)sizeof(staticLengths)) {
+utf8Lengths=staticLengths;
+} else {
+utf8Lengths=(int32_t *)uprv_malloc(allocSize);
+if(utf8Lengths==NULL) {
+maxLength16=maxLength8=0;  // Prevent usage by making needsStringSpanUTF16/8() return FALSE.
+return;  // Out of memory.
+}
+}
+if(all) {
+// Store span lengths for all span() variants.
+spanLengths=(uint8_t *)(utf8Lengths+stringsLength);
+spanBackLengths=spanLengths+stringsLength;
+spanUTF8Lengths=spanBackLengths+stringsLength;
+spanBackUTF8Lengths=spanUTF8Lengths+stringsLength;
+utf8=spanBackUTF8Lengths+stringsLength;
+} else {
+// Store span lengths for only one span() variant.
+if(which&UTF8) {
+spanLengths=(uint8_t *)(utf8Lengths+stringsLength);
+utf8=spanLengths+stringsLength;
+} else {
+spanLengths=(uint8_t *)utf8Lengths;
+}
+spanBackLengths=spanUTF8Lengths=spanBackUTF8Lengths=spanLengths;
+}
+// Set the meta data and pSpanNotSet and write the UTF-8 strings.
+int32_t utf8Count=0;  // Count UTF-8 bytes written so far.
+for(i=0; i<stringsLength; ++i) {
+const UnicodeString &string=*(const UnicodeString *)strings.elementAt(i);
+const UChar *s16=string.getBuffer();
+int32_t length16=string.length();
+spanLength=spanSet.span(s16, length16, USET_SPAN_CONTAINED);
+if(spanLength<length16) {  // Relevant string.
+if(which&UTF16) {
+if(which&CONTAINED) {
+if(which&FWD) {
+spanLengths[i]=makeSpanLengthByte(spanLength);
+}
+if(which&BACK) {
+spanLength=length16-spanSet.spanBack(s16, length16, USET_SPAN_CONTAINED);
+spanBackLengths[i]=makeSpanLengthByte(spanLength);
+}
+} else /* not CONTAINED, not all, but NOT_CONTAINED */ {
+spanLengths[i]=spanBackLengths[i]=0;  // Only store a relevant/irrelevant flag.
+}
+}
+if(which&UTF8) {
+uint8_t *s8=utf8+utf8Count;
+int32_t length8=appendUTF8(s16, length16, s8, utf8Length-utf8Count);
+utf8Count+=utf8Lengths[i]=length8;
+if(length8==0) {  // Irrelevant for UTF-8 because not representable in UTF-8.
+spanUTF8Lengths[i]=spanBackUTF8Lengths[i]=(uint8_t)ALL_CP_CONTAINED;
+} else {  // Relevant for UTF-8.
+if(which&CONTAINED) {
+if(which&FWD) {
+spanLength=spanSet.spanUTF8((const char *)s8, length8, USET_SPAN_CONTAINED);
+spanUTF8Lengths[i]=makeSpanLengthByte(spanLength);
+}
+if(which&BACK) {
+spanLength=length8-spanSet.spanBackUTF8((const char *)s8, length8, USET_SPAN_CONTAINED);
+spanBackUTF8Lengths[i]=makeSpanLengthByte(spanLength);
+}
+} else /* not CONTAINED, not all, but NOT_CONTAINED */ {
+spanUTF8Lengths[i]=spanBackUTF8Lengths[i]=0;  // Only store a relevant/irrelevant flag.
+}
+}
+}
+if(which&NOT_CONTAINED) {
+// Add string start and end code points to the spanNotSet so that
+// a span(while not contained) stops before any string.
+UChar32 c;
+if(which&FWD) {
+int32_t len=0;
+U16_NEXT(s16, len, length16, c);
+addToSpanNotSet(c);
+}
+if(which&BACK) {
+int32_t len=length16;
+U16_PREV(s16, 0, len, c);
+addToSpanNotSet(c);
+}
+}
+} else {  // Irrelevant string.
+if(which&UTF8) {
+if(which&CONTAINED) {  // Only necessary for LONGEST_MATCH.
+uint8_t *s8=utf8+utf8Count;
+int32_t length8=appendUTF8(s16, length16, s8, utf8Length-utf8Count);
+utf8Count+=utf8Lengths[i]=length8;
+} else {
+utf8Lengths[i]=0;
+}
+}
+if(all) {
+spanLengths[i]=spanBackLengths[i]=
+spanUTF8Lengths[i]=spanBackUTF8Lengths[i]=
+(uint8_t)ALL_CP_CONTAINED;
+} else {
+// All spanXYZLengths pointers contain the same address.
+spanLengths[i]=(uint8_t)ALL_CP_CONTAINED;
+}
+}
+}
+// Finish.
+if(all) {
+pSpanNotSet->freeze();
+}
+}
+// Copy constructor. Assumes which==ALL for a frozen set.
+UnicodeSetStringSpan::UnicodeSetStringSpan(const UnicodeSetStringSpan &otherStringSpan,
+const UVector &newParentSetStrings)
+: spanSet(otherStringSpan.spanSet), pSpanNotSet(NULL), strings(newParentSetStrings),
+utf8Lengths(NULL), spanLengths(NULL), utf8(NULL),
+utf8Length(otherStringSpan.utf8Length),
+maxLength16(otherStringSpan.maxLength16), maxLength8(otherStringSpan.maxLength8),
+all(TRUE) {
+if(otherStringSpan.pSpanNotSet==&otherStringSpan.spanSet) {
+pSpanNotSet=&spanSet;
+} else {
+pSpanNotSet=(UnicodeSet *)otherStringSpan.pSpanNotSet->clone();
+}
+// Allocate a block of meta data.
+// UTF-8 lengths, 4 sets of span lengths, UTF-8 strings.
+int32_t stringsLength=strings.size();
+int32_t allocSize=stringsLength*(4+1+1+1+1)+utf8Length;
+if(allocSize<=(int32_t)sizeof(staticLengths)) {
+utf8Lengths=staticLengths;
+} else {
+utf8Lengths=(int32_t *)uprv_malloc(allocSize);
+if(utf8Lengths==NULL) {
+maxLength16=maxLength8=0;  // Prevent usage by making needsStringSpanUTF16/8() return FALSE.
+return;  // Out of memory.
+}
+}
+spanLengths=(uint8_t *)(utf8Lengths+stringsLength);
+utf8=spanLengths+stringsLength*4;
+uprv_memcpy(utf8Lengths, otherStringSpan.utf8Lengths, allocSize);
+}
+UnicodeSetStringSpan::~UnicodeSetStringSpan() {
+if(pSpanNotSet!=NULL && pSpanNotSet!=&spanSet) {
+delete pSpanNotSet;
+}
+if(utf8Lengths!=NULL && utf8Lengths!=staticLengths) {
+uprv_free(utf8Lengths);
+}
+}
+void UnicodeSetStringSpan::addToSpanNotSet(UChar32 c) {
+if(pSpanNotSet==NULL || pSpanNotSet==&spanSet) {
+if(spanSet.contains(c)) {
+return;  // Nothing to do.
+}
+UnicodeSet *newSet=(UnicodeSet *)spanSet.cloneAsThawed();
+if(newSet==NULL) {
+return;  // Out of memory.
+} else {
+pSpanNotSet=newSet;
+}
+}
+pSpanNotSet->add(c);
+}
+// Compare strings without any argument checks. Requires length>0.
+static inline UBool
+matches16(const UChar *s, const UChar *t, int32_t length) {
+do {
+if(*s++!=*t++) {
+return FALSE;
+}
+} while(--length>0);
+return TRUE;
+}
+static inline UBool
+matches8(const uint8_t *s, const uint8_t *t, int32_t length) {
+do {
+if(*s++!=*t++) {
+return FALSE;
+}
+} while(--length>0);
+return TRUE;
+}
+// Compare 16-bit Unicode strings (which may be malformed UTF-16)
+// at code point boundaries.
+// That is, each edge of a match must not be in the middle of a surrogate pair.
+static inline UBool
+matches16CPB(const UChar *s, int32_t start, int32_t limit, const UChar *t, int32_t length) {
+s+=start;
+limit-=start;
+return matches16(s, t, length) &&
+!(0<start && U16_IS_LEAD(s[-1]) && U16_IS_TRAIL(s[0])) &&
+!(length<limit && U16_IS_LEAD(s[length-1]) && U16_IS_TRAIL(s[length]));
+}
+// Does the set contain the next code point?
+// If so, return its length; otherwise return its negative length.
+static inline int32_t
+spanOne(const UnicodeSet &set, const UChar *s, int32_t length) {
+UChar c=*s, c2;
+if(c>=0xd800 && c<=0xdbff && length>=2 && U16_IS_TRAIL(c2=s[1])) {
+return set.contains(U16_GET_SUPPLEMENTARY(c, c2)) ? 2 : -2;
+}
+return set.contains(c) ? 1 : -1;
+}
+static inline int32_t
+spanOneBack(const UnicodeSet &set, const UChar *s, int32_t length) {
+UChar c=s[length-1], c2;
+if(c>=0xdc00 && c<=0xdfff && length>=2 && U16_IS_LEAD(c2=s[length-2])) {
+return set.contains(U16_GET_SUPPLEMENTARY(c2, c)) ? 2 : -2;
+}
+return set.contains(c) ? 1 : -1;
+}
+static inline int32_t
+spanOneUTF8(const UnicodeSet &set, const uint8_t *s, int32_t length) {
+UChar32 c=*s;
+if((int8_t)c>=0) {
+return set.contains(c) ? 1 : -1;
+}
+// Take advantage of non-ASCII fastpaths in U8_NEXT_OR_FFFD().
+int32_t i=0;
+U8_NEXT_OR_FFFD(s, i, length, c);
+return set.contains(c) ? i : -i;
+}
+static inline int32_t
+spanOneBackUTF8(const UnicodeSet &set, const uint8_t *s, int32_t length) {
+UChar32 c=s[length-1];
+if((int8_t)c>=0) {
+return set.contains(c) ? 1 : -1;
+}
+int32_t i=length-1;
+c=utf8_prevCharSafeBody(s, 0, &i, c, -3);
+length-=i;
+return set.contains(c) ? length : -length;
+}
+/*
+* Note: In span() when spanLength==0 (after a string match, or at the beginning
+* after an empty code point span) and in spanNot() and spanNotUTF8(),
+* string matching could use a binary search
+* because all string matches are done from the same start index.
+*
+* For UTF-8, this would require a comparison function that returns UTF-16 order.
+*
+* This optimization should not be necessary for normal UnicodeSets because
+* most sets have no strings, and most sets with strings have
+* very few very short strings.
+* For cases with many strings, it might be better to use a different API
+* and implementation with a DFA (state machine).
+*/
+/*
+* Algorithm for span(USET_SPAN_CONTAINED)
+*
+* Theoretical algorithm:
+* - Iterate through the string, and at each code point boundary:
+*   + If the code point there is in the set, then remember to continue after it.
+*   + If a set string matches at the current position, then remember to continue after it.
+*   + Either recursively span for each code point or string match,
+*     or recursively span for all but the shortest one and
+*     iteratively continue the span with the shortest local match.
+*   + Remember the longest recursive span (the farthest end point).
+*   + If there is no match at the current position, neither for the code point there
+*     nor for any set string, then stop and return the longest recursive span length.
+*
+* Optimized implementation:
+*
+* (We assume that most sets will have very few very short strings.
+* A span using a string-less set is extremely fast.)
+*
+* Create and cache a spanSet which contains all of the single code points
+* of the original set but none of its strings.
+*
+* - Start with spanLength=spanSet.span(USET_SPAN_CONTAINED).
+* - Loop:
+*   + Try to match each set string at the end of the spanLength.
+*     ~ Set strings that start with set-contained code points must be matched
+*       with a partial overlap because the recursive algorithm would have tried
+*       to match them at every position.
+*     ~ Set strings that entirely consist of set-contained code points
+*       are irrelevant for span(USET_SPAN_CONTAINED) because the
+*       recursive algorithm would continue after them anyway
+*       and find the longest recursive match from their end.
+*     ~ Rather than recursing, note each end point of a set string match.
+*   + If no set string matched after spanSet.span(), then return
+*     with where the spanSet.span() ended.
+*   + If at least one set string matched after spanSet.span(), then
+*     pop the shortest string match end point and continue
+*     the loop, trying to match all set strings from there.
+*   + If at least one more set string matched after a previous string match,
+*     then test if the code point after the previous string match is also
+*     contained in the set.
+*     Continue the loop with the shortest end point of either this code point
+*     or a matching set string.
+*   + If no more set string matched after a previous string match,
+*     then try another spanLength=spanSet.span(USET_SPAN_CONTAINED).
+*     Stop if spanLength==0, otherwise continue the loop.
+*
+* By noting each end point of a set string match,
+* the function visits each string position at most once and finishes
+* in linear time.
+*
+* The recursive algorithm may visit the same string position many times
+* if multiple paths lead to it and finishes in exponential time.
+*/
+/*
+* Algorithm for span(USET_SPAN_SIMPLE)
+*
+* Theoretical algorithm:
+* - Iterate through the string, and at each code point boundary:
+*   + If the code point there is in the set, then remember to continue after it.
+*   + If a set string matches at the current position, then remember to continue after it.
+*   + Continue from the farthest match position and ignore all others.
+*   + If there is no match at the current position,
+*     then stop and return the current position.
+*
+* Optimized implementation:
+*
+* (Same assumption and spanSet as above.)
+*
+* - Start with spanLength=spanSet.span(USET_SPAN_CONTAINED).
+* - Loop:
+*   + Try to match each set string at the end of the spanLength.
+*     ~ Set strings that start with set-contained code points must be matched
+*       with a partial overlap because the standard algorithm would have tried
+*       to match them earlier.
+*     ~ Set strings that entirely consist of set-contained code points
+*       must be matched with a full overlap because the longest-match algorithm
+*       would hide set string matches that end earlier.
+*       Such set strings need not be matched earlier inside the code point span
+*       because the standard algorithm would then have continued after
+*       the set string match anyway.
+*     ~ Remember the longest set string match (farthest end point) from the earliest
+*       starting point.
+*   + If no set string matched after spanSet.span(), then return
+*     with where the spanSet.span() ended.
+*   + If at least one set string matched, then continue the loop after the
+*     longest match from the earliest position.
+*   + If no more set string matched after a previous string match,
+*     then try another spanLength=spanSet.span(USET_SPAN_CONTAINED).
+*     Stop if spanLength==0, otherwise continue the loop.
+*/
+int32_t UnicodeSetStringSpan::span(const UChar *s, int32_t length, USetSpanCondition spanCondition) const {
+if(spanCondition==USET_SPAN_NOT_CONTAINED) {
+return spanNot(s, length);
+}
+int32_t spanLength=spanSet.span(s, length, USET_SPAN_CONTAINED);
+if(spanLength==length) {
+return length;
+}
+// Consider strings; they may overlap with the span.
+OffsetList offsets;
+if(spanCondition==USET_SPAN_CONTAINED) {
+// Use offset list to try all possibilities.
+offsets.setMaxLength(maxLength16);
+}
+int32_t pos=spanLength, rest=length-pos;
+int32_t i, stringsLength=strings.size();
+for(;;) {
+if(spanCondition==USET_SPAN_CONTAINED) {
+for(i=0; i<stringsLength; ++i) {
+int32_t overlap=spanLengths[i];
+if(overlap==ALL_CP_CONTAINED) {
+continue;  // Irrelevant string.
+}
+const UnicodeString &string=*(const UnicodeString *)strings.elementAt(i);
+const UChar *s16=string.getBuffer();
+int32_t length16=string.length();
+// Try to match this string at pos-overlap..pos.
+if(overlap>=LONG_SPAN) {
+overlap=length16;
+// While contained: No point matching fully inside the code point span.
+U16_BACK_1(s16, 0, overlap);  // Length of the string minus the last code point.
+}
+if(overlap>spanLength) {
+overlap=spanLength;
+}
+int32_t inc=length16-overlap;  // Keep overlap+inc==length16.
+for(;;) {
+if(inc>rest) {
+break;
+}
+// Try to match if the increment is not listed already.
+if(!offsets.containsOffset(inc) && matches16CPB(s, pos-overlap, length, s16, length16)) {
+if(inc==rest) {
+return length;  // Reached the end of the string.
+}
+offsets.addOffset(inc);
+}
+if(overlap==0) {
+break;
+}
+--overlap;
+++inc;
+}
+}
+} else /* USET_SPAN_SIMPLE */ {
+int32_t maxInc=0, maxOverlap=0;
+for(i=0; i<stringsLength; ++i) {
+int32_t overlap=spanLengths[i];
+// For longest match, we do need to try to match even an all-contained string
+// to find the match from the earliest start.
+const UnicodeString &string=*(const UnicodeString *)strings.elementAt(i);
+const UChar *s16=string.getBuffer();
+int32_t length16=string.length();
+// Try to match this string at pos-overlap..pos.
+if(overlap>=LONG_SPAN) {
+overlap=length16;
+// Longest match: Need to match fully inside the code point span
+// to find the match from the earliest start.
+}
+if(overlap>spanLength) {
+overlap=spanLength;
+}
+int32_t inc=length16-overlap;  // Keep overlap+inc==length16.
+for(;;) {
+if(inc>rest || overlap<maxOverlap) {
+break;
+}
+// Try to match if the string is longer or starts earlier.
+if( (overlap>maxOverlap || /* redundant overlap==maxOverlap && */ inc>maxInc) &&
+matches16CPB(s, pos-overlap, length, s16, length16)
+) {
+maxInc=inc;  // Longest match from earliest start.
+maxOverlap=overlap;
+break;
+}
+--overlap;
+++inc;
+}
+}
+if(maxInc!=0 || maxOverlap!=0) {
+// Longest-match algorithm, and there was a string match.
+// Simply continue after it.
+pos+=maxInc;
+rest-=maxInc;
+if(rest==0) {
+return length;  // Reached the end of the string.
+}
+spanLength=0;  // Match strings from after a string match.
+continue;
+}
+}
+// Finished trying to match all strings at pos.
+if(spanLength!=0 || pos==0) {
+// The position is after an unlimited code point span (spanLength!=0),
+// not after a string match.
+// The only position where spanLength==0 after a span is pos==0.
+// Otherwise, an unlimited code point span is only tried again when no
+// strings match, and if such a non-initial span fails we stop.
+if(offsets.isEmpty()) {
+return pos;  // No strings matched after a span.
+}
+// Match strings from after the next string match.
+} else {
+// The position is after a string match (or a single code point).
+if(offsets.isEmpty()) {
+// No more strings matched after a previous string match.
+// Try another code point span from after the last string match.
+spanLength=spanSet.span(s+pos, rest, USET_SPAN_CONTAINED);
+if( spanLength==rest || // Reached the end of the string, or
+spanLength==0       // neither strings nor span progressed.
+) {
+return pos+spanLength;
+}
+pos+=spanLength;
+rest-=spanLength;
+continue;  // spanLength>0: Match strings from after a span.
+} else {
+// Try to match only one code point from after a string match if some
+// string matched beyond it, so that we try all possible positions
+// and don't overshoot.
+spanLength=spanOne(spanSet, s+pos, rest);
+if(spanLength>0) {
+if(spanLength==rest) {
+return length;  // Reached the end of the string.
+}
+// Match strings after this code point.
+// There cannot be any increments below it because UnicodeSet strings
+// contain multiple code points.
+pos+=spanLength;
+rest-=spanLength;
+offsets.shift(spanLength);
+spanLength=0;
+continue;  // Match strings from after a single code point.
+}
+// Match strings from after the next string match.
+}
+}
+int32_t minOffset=offsets.popMinimum();
+pos+=minOffset;
+rest-=minOffset;
+spanLength=0;  // Match strings from after a string match.
+}
+}
+int32_t UnicodeSetStringSpan::spanBack(const UChar *s, int32_t length, USetSpanCondition spanCondition) const {
+if(spanCondition==USET_SPAN_NOT_CONTAINED) {
+return spanNotBack(s, length);
+}
+int32_t pos=spanSet.spanBack(s, length, USET_SPAN_CONTAINED);
+if(pos==0) {
+return 0;
+}
+int32_t spanLength=length-pos;
+// Consider strings; they may overlap with the span.
+OffsetList offsets;
+if(spanCondition==USET_SPAN_CONTAINED) {
+// Use offset list to try all possibilities.
+offsets.setMaxLength(maxLength16);
+}
+int32_t i, stringsLength=strings.size();
+uint8_t *spanBackLengths=spanLengths;
+if(all) {
+spanBackLengths+=stringsLength;
+}
+for(;;) {
+if(spanCondition==USET_SPAN_CONTAINED) {
+for(i=0; i<stringsLength; ++i) {
+int32_t overlap=spanBackLengths[i];
+if(overlap==ALL_CP_CONTAINED) {
+continue;  // Irrelevant string.
+}
+const UnicodeString &string=*(const UnicodeString *)strings.elementAt(i);
+const UChar *s16=string.getBuffer();
+int32_t length16=string.length();
+// Try to match this string at pos-(length16-overlap)..pos-length16.
+if(overlap>=LONG_SPAN) {
+overlap=length16;
+// While contained: No point matching fully inside the code point span.
+int32_t len1=0;
+U16_FWD_1(s16, len1, overlap);
+overlap-=len1;  // Length of the string minus the first code point.
+}
+if(overlap>spanLength) {
+overlap=spanLength;
+}
+int32_t dec=length16-overlap;  // Keep dec+overlap==length16.
+for(;;) {
+if(dec>pos) {
+break;
+}
+// Try to match if the decrement is not listed already.
+if(!offsets.containsOffset(dec) && matches16CPB(s, pos-dec, length, s16, length16)) {
+if(dec==pos) {
+return 0;  // Reached the start of the string.
+}
+offsets.addOffset(dec);
+}
+if(overlap==0) {
+break;
+}
+--overlap;
+++dec;
+}
+}
+} else /* USET_SPAN_SIMPLE */ {
+int32_t maxDec=0, maxOverlap=0;
+for(i=0; i<stringsLength; ++i) {
+int32_t overlap=spanBackLengths[i];
+// For longest match, we do need to try to match even an all-contained string
+// to find the match from the latest end.
+const UnicodeString &string=*(const UnicodeString *)strings.elementAt(i);
+const UChar *s16=string.getBuffer();
+int32_t length16=string.length();
+// Try to match this string at pos-(length16-overlap)..pos-length16.
+if(overlap>=LONG_SPAN) {
+overlap=length16;
+// Longest match: Need to match fully inside the code point span
+// to find the match from the latest end.
+}
+if(overlap>spanLength) {
+overlap=spanLength;
+}
+int32_t dec=length16-overlap;  // Keep dec+overlap==length16.
+for(;;) {
+if(dec>pos || overlap<maxOverlap) {
+break;
+}
+// Try to match if the string is longer or ends later.
+if( (overlap>maxOverlap || /* redundant overlap==maxOverlap && */ dec>maxDec) &&
+matches16CPB(s, pos-dec, length, s16, length16)
+) {
+maxDec=dec;  // Longest match from latest end.
+maxOverlap=overlap;
+break;
+}
+--overlap;
+++dec;
+}
+}
+if(maxDec!=0 || maxOverlap!=0) {
+// Longest-match algorithm, and there was a string match.
+// Simply continue before it.
+pos-=maxDec;
+if(pos==0) {
+return 0;  // Reached the start of the string.
+}
+spanLength=0;  // Match strings from before a string match.
+continue;
+}
+}
+// Finished trying to match all strings at pos.
+if(spanLength!=0 || pos==length) {
+// The position is before an unlimited code point span (spanLength!=0),
+// not before a string match.
+// The only position where spanLength==0 before a span is pos==length.
+// Otherwise, an unlimited code point span is only tried again when no
+// strings match, and if such a non-initial span fails we stop.
+if(offsets.isEmpty()) {
+return pos;  // No strings matched before a span.
+}
+// Match strings from before the next string match.
+} else {
+// The position is before a string match (or a single code point).
+if(offsets.isEmpty()) {
+// No more strings matched before a previous string match.
+// Try another code point span from before the last string match.
+int32_t oldPos=pos;
+pos=spanSet.spanBack(s, oldPos, USET_SPAN_CONTAINED);
+spanLength=oldPos-pos;
+if( pos==0 ||           // Reached the start of the string, or
+spanLength==0       // neither strings nor span progressed.
+) {
+return pos;
+}
+continue;  // spanLength>0: Match strings from before a span.
+} else {
+// Try to match only one code point from before a string match if some
+// string matched beyond it, so that we try all possible positions
+// and don't overshoot.
+spanLength=spanOneBack(spanSet, s, pos);
+if(spanLength>0) {
+if(spanLength==pos) {
+return 0;  // Reached the start of the string.
+}
+// Match strings before this code point.
+// There cannot be any decrements below it because UnicodeSet strings
+// contain multiple code points.
+pos-=spanLength;
+offsets.shift(spanLength);
+spanLength=0;
+continue;  // Match strings from before a single code point.
+}
+// Match strings from before the next string match.
+}
+}
+pos-=offsets.popMinimum();
+spanLength=0;  // Match strings from before a string match.
+}
+}
+int32_t UnicodeSetStringSpan::spanUTF8(const uint8_t *s, int32_t length, USetSpanCondition spanCondition) const {
+if(spanCondition==USET_SPAN_NOT_CONTAINED) {
+return spanNotUTF8(s, length);
+}
+int32_t spanLength=spanSet.spanUTF8((const char *)s, length, USET_SPAN_CONTAINED);
+if(spanLength==length) {
+return length;
+}
+// Consider strings; they may overlap with the span.
+OffsetList offsets;
+if(spanCondition==USET_SPAN_CONTAINED) {
+// Use offset list to try all possibilities.
+offsets.setMaxLength(maxLength8);
+}
+int32_t pos=spanLength, rest=length-pos;
+int32_t i, stringsLength=strings.size();
+uint8_t *spanUTF8Lengths=spanLengths;
+if(all) {
+spanUTF8Lengths+=2*stringsLength;
+}
+for(;;) {
+const uint8_t *s8=utf8;
+int32_t length8;
+if(spanCondition==USET_SPAN_CONTAINED) {
+for(i=0; i<stringsLength; ++i) {
+length8=utf8Lengths[i];
+if(length8==0) {
+continue;  // String not representable in UTF-8.
+}
+int32_t overlap=spanUTF8Lengths[i];
+if(overlap==ALL_CP_CONTAINED) {
+s8+=length8;
+continue;  // Irrelevant string.
+}
+// Try to match this string at pos-overlap..pos.
+if(overlap>=LONG_SPAN) {
+overlap=length8;
+// While contained: No point matching fully inside the code point span.
+U8_BACK_1(s8, 0, overlap);  // Length of the string minus the last code point.
+}
+if(overlap>spanLength) {
+overlap=spanLength;
+}
+int32_t inc=length8-overlap;  // Keep overlap+inc==length8.
+for(;;) {
+if(inc>rest) {
+break;
+}
+// Try to match if the increment is not listed already.
+// Match at code point boundaries. (The UTF-8 strings were converted
+// from UTF-16 and are guaranteed to be well-formed.)
+if( !U8_IS_TRAIL(s[pos-overlap]) &&
+!offsets.containsOffset(inc) &&
+matches8(s+pos-overlap, s8, length8)
+) {
+if(inc==rest) {
+return length;  // Reached the end of the string.
+}
+offsets.addOffset(inc);
+}
+if(overlap==0) {
+break;
+}
+--overlap;
+++inc;
+}
+s8+=length8;
+}
+} else /* USET_SPAN_SIMPLE */ {
+int32_t maxInc=0, maxOverlap=0;
+for(i=0; i<stringsLength; ++i) {
+length8=utf8Lengths[i];
+if(length8==0) {
+continue;  // String not representable in UTF-8.
+}
+int32_t overlap=spanUTF8Lengths[i];
+// For longest match, we do need to try to match even an all-contained string
+// to find the match from the earliest start.
+// Try to match this string at pos-overlap..pos.
+if(overlap>=LONG_SPAN) {
+overlap=length8;
+// Longest match: Need to match fully inside the code point span
+// to find the match from the earliest start.
+}
+if(overlap>spanLength) {
+overlap=spanLength;
+}
+int32_t inc=length8-overlap;  // Keep overlap+inc==length8.
+for(;;) {
+if(inc>rest || overlap<maxOverlap) {
+break;
+}
+// Try to match if the string is longer or starts earlier.
+// Match at code point boundaries. (The UTF-8 strings were converted
+// from UTF-16 and are guaranteed to be well-formed.)
+if( !U8_IS_TRAIL(s[pos-overlap]) &&
+(overlap>maxOverlap || /* redundant overlap==maxOverlap && */ inc>maxInc) &&
+matches8(s+pos-overlap, s8, length8)
+) {
+maxInc=inc;  // Longest match from earliest start.
+maxOverlap=overlap;
+break;
+}
+--overlap;
+++inc;
+}
+s8+=length8;
+}
+if(maxInc!=0 || maxOverlap!=0) {
+// Longest-match algorithm, and there was a string match.
+// Simply continue after it.
+pos+=maxInc;
+rest-=maxInc;
+if(rest==0) {
+return length;  // Reached the end of the string.
+}
+spanLength=0;  // Match strings from after a string match.
+continue;
+}
+}
+// Finished trying to match all strings at pos.
+if(spanLength!=0 || pos==0) {
+// The position is after an unlimited code point span (spanLength!=0),
+// not after a string match.
+// The only position where spanLength==0 after a span is pos==0.
+// Otherwise, an unlimited code point span is only tried again when no
+// strings match, and if such a non-initial span fails we stop.
+if(offsets.isEmpty()) {
+return pos;  // No strings matched after a span.
+}
+// Match strings from after the next string match.
+} else {
+// The position is after a string match (or a single code point).
+if(offsets.isEmpty()) {
+// No more strings matched after a previous string match.
+// Try another code point span from after the last string match.
+spanLength=spanSet.spanUTF8((const char *)s+pos, rest, USET_SPAN_CONTAINED);
+if( spanLength==rest || // Reached the end of the string, or
+spanLength==0       // neither strings nor span progressed.
+) {
+return pos+spanLength;
+}
+pos+=spanLength;
+rest-=spanLength;
+continue;  // spanLength>0: Match strings from after a span.
+} else {
+// Try to match only one code point from after a string match if some
+// string matched beyond it, so that we try all possible positions
+// and don't overshoot.
+spanLength=spanOneUTF8(spanSet, s+pos, rest);
+if(spanLength>0) {
+if(spanLength==rest) {
+return length;  // Reached the end of the string.
+}
+// Match strings after this code point.
+// There cannot be any increments below it because UnicodeSet strings
+// contain multiple code points.
+pos+=spanLength;
+rest-=spanLength;
+offsets.shift(spanLength);
+spanLength=0;
+continue;  // Match strings from after a single code point.
+}
+// Match strings from after the next string match.
+}
+}
+int32_t minOffset=offsets.popMinimum();
+pos+=minOffset;
+rest-=minOffset;
+spanLength=0;  // Match strings from after a string match.
+}
+}
+int32_t UnicodeSetStringSpan::spanBackUTF8(const uint8_t *s, int32_t length, USetSpanCondition spanCondition) const {
+if(spanCondition==USET_SPAN_NOT_CONTAINED) {
+return spanNotBackUTF8(s, length);
+}
+int32_t pos=spanSet.spanBackUTF8((const char *)s, length, USET_SPAN_CONTAINED);
+if(pos==0) {
+return 0;
+}
+int32_t spanLength=length-pos;
+// Consider strings; they may overlap with the span.
+OffsetList offsets;
+if(spanCondition==USET_SPAN_CONTAINED) {
+// Use offset list to try all possibilities.
+offsets.setMaxLength(maxLength8);
+}
+int32_t i, stringsLength=strings.size();
+uint8_t *spanBackUTF8Lengths=spanLengths;
+if(all) {
+spanBackUTF8Lengths+=3*stringsLength;
+}
+for(;;) {
+const uint8_t *s8=utf8;
+int32_t length8;
+if(spanCondition==USET_SPAN_CONTAINED) {
+for(i=0; i<stringsLength; ++i) {
+length8=utf8Lengths[i];
+if(length8==0) {
+continue;  // String not representable in UTF-8.
+}
+int32_t overlap=spanBackUTF8Lengths[i];
+if(overlap==ALL_CP_CONTAINED) {
+s8+=length8;
+continue;  // Irrelevant string.
+}
+// Try to match this string at pos-(length8-overlap)..pos-length8.
+if(overlap>=LONG_SPAN) {
+overlap=length8;
+// While contained: No point matching fully inside the code point span.
+int32_t len1=0;
+U8_FWD_1(s8, len1, overlap);
+overlap-=len1;  // Length of the string minus the first code point.
+}
+if(overlap>spanLength) {
+overlap=spanLength;
+}
+int32_t dec=length8-overlap;  // Keep dec+overlap==length8.
+for(;;) {
+if(dec>pos) {
+break;
+}
+// Try to match if the decrement is not listed already.
+// Match at code point boundaries. (The UTF-8 strings were converted
+// from UTF-16 and are guaranteed to be well-formed.)
+if( !U8_IS_TRAIL(s[pos-dec]) &&
+!offsets.containsOffset(dec) &&
+matches8(s+pos-dec, s8, length8)
+) {
+if(dec==pos) {
+return 0;  // Reached the start of the string.
+}
+offsets.addOffset(dec);
+}
+if(overlap==0) {
+break;
+}
+--overlap;
+++dec;
+}
+s8+=length8;
+}
+} else /* USET_SPAN_SIMPLE */ {
+int32_t maxDec=0, maxOverlap=0;
+for(i=0; i<stringsLength; ++i) {
+length8=utf8Lengths[i];
+if(length8==0) {
+continue;  // String not representable in UTF-8.
+}
+int32_t overlap=spanBackUTF8Lengths[i];
+// For longest match, we do need to try to match even an all-contained string
+// to find the match from the latest end.
+// Try to match this string at pos-(length8-overlap)..pos-length8.
+if(overlap>=LONG_SPAN) {
+overlap=length8;
+// Longest match: Need to match fully inside the code point span
+// to find the match from the latest end.
+}
+if(overlap>spanLength) {
+overlap=spanLength;
+}
+int32_t dec=length8-overlap;  // Keep dec+overlap==length8.
+for(;;) {
+if(dec>pos || overlap<maxOverlap) {
+break;
+}
+// Try to match if the string is longer or ends later.
+// Match at code point boundaries. (The UTF-8 strings were converted
+// from UTF-16 and are guaranteed to be well-formed.)
+if( !U8_IS_TRAIL(s[pos-dec]) &&
+(overlap>maxOverlap || /* redundant overlap==maxOverlap && */ dec>maxDec) &&
+matches8(s+pos-dec, s8, length8)
+) {
+maxDec=dec;  // Longest match from latest end.
+maxOverlap=overlap;
+break;
+}
+--overlap;
+++dec;
+}
+s8+=length8;
+}
+if(maxDec!=0 || maxOverlap!=0) {
+// Longest-match algorithm, and there was a string match.
+// Simply continue before it.
+pos-=maxDec;
+if(pos==0) {
+return 0;  // Reached the start of the string.
+}
+spanLength=0;  // Match strings from before a string match.
+continue;
+}
+}
+// Finished trying to match all strings at pos.
+if(spanLength!=0 || pos==length) {
+// The position is before an unlimited code point span (spanLength!=0),
+// not before a string match.
+// The only position where spanLength==0 before a span is pos==length.
+// Otherwise, an unlimited code point span is only tried again when no
+// strings match, and if such a non-initial span fails we stop.
+if(offsets.isEmpty()) {
+return pos;  // No strings matched before a span.
+}
+// Match strings from before the next string match.
+} else {
+// The position is before a string match (or a single code point).
+if(offsets.isEmpty()) {
+// No more strings matched before a previous string match.
+// Try another code point span from before the last string match.
+int32_t oldPos=pos;
+pos=spanSet.spanBackUTF8((const char *)s, oldPos, USET_SPAN_CONTAINED);
+spanLength=oldPos-pos;
+if( pos==0 ||           // Reached the start of the string, or
+spanLength==0       // neither strings nor span progressed.
+) {
+return pos;
+}
+continue;  // spanLength>0: Match strings from before a span.
+} else {
+// Try to match only one code point from before a string match if some
+// string matched beyond it, so that we try all possible positions
+// and don't overshoot.
+spanLength=spanOneBackUTF8(spanSet, s, pos);
+if(spanLength>0) {
+if(spanLength==pos) {
+return 0;  // Reached the start of the string.
+}
+// Match strings before this code point.
+// There cannot be any decrements below it because UnicodeSet strings
+// contain multiple code points.
+pos-=spanLength;
+offsets.shift(spanLength);
+spanLength=0;
+continue;  // Match strings from before a single code point.
+}
+// Match strings from before the next string match.
+}
+}
+pos-=offsets.popMinimum();
+spanLength=0;  // Match strings from before a string match.
+}
+}
+/*
+* Algorithm for spanNot()==span(USET_SPAN_NOT_CONTAINED)
+*
+* Theoretical algorithm:
+* - Iterate through the string, and at each code point boundary:
+*   + If the code point there is in the set, then return with the current position.
+*   + If a set string matches at the current position, then return with the current position.
+*
+* Optimized implementation:
+*
+* (Same assumption as for span() above.)
+*
+* Create and cache a spanNotSet which contains all of the single code points
+* of the original set but none of its strings.
+* For each set string add its initial code point to the spanNotSet.
+* (Also add its final code point for spanNotBack().)
+*
+* - Loop:
+*   + Do spanLength=spanNotSet.span(USET_SPAN_NOT_CONTAINED).
+*   + If the current code point is in the original set, then
+*     return the current position.
+*   + If any set string matches at the current position, then
+*     return the current position.
+*   + If there is no match at the current position, neither for the code point there
+*     nor for any set string, then skip this code point and continue the loop.
+*     This happens for set-string-initial code points that were added to spanNotSet
+*     when there is not actually a match for such a set string.
+*/
+int32_t UnicodeSetStringSpan::spanNot(const UChar *s, int32_t length) const {
+int32_t pos=0, rest=length;
+int32_t i, stringsLength=strings.size();
+do {
+// Span until we find a code point from the set,
+// or a code point that starts or ends some string.
+i=pSpanNotSet->span(s+pos, rest, USET_SPAN_NOT_CONTAINED);
+if(i==rest) {
+return length;  // Reached the end of the string.
+}
+pos+=i;
+rest-=i;
+// Check whether the current code point is in the original set,
+// without the string starts and ends.
+int32_t cpLength=spanOne(spanSet, s+pos, rest);
+if(cpLength>0) {
+return pos;  // There is a set element at pos.
+}
+// Try to match the strings at pos.
+for(i=0; i<stringsLength; ++i) {
+if(spanLengths[i]==ALL_CP_CONTAINED) {
+continue;  // Irrelevant string.
+}
+const UnicodeString &string=*(const UnicodeString *)strings.elementAt(i);
+const UChar *s16=string.getBuffer();
+int32_t length16=string.length();
+if(length16<=rest && matches16CPB(s, pos, length, s16, length16)) {
+return pos;  // There is a set element at pos.
+}
+}
+// The span(while not contained) ended on a string start/end which is
+// not in the original set. Skip this code point and continue.
+// cpLength<0
+pos-=cpLength;
+rest+=cpLength;
+} while(rest!=0);
+return length;  // Reached the end of the string.
+}
+int32_t UnicodeSetStringSpan::spanNotBack(const UChar *s, int32_t length) const {
+int32_t pos=length;
+int32_t i, stringsLength=strings.size();
+do {
+// Span until we find a code point from the set,
+// or a code point that starts or ends some string.
+pos=pSpanNotSet->spanBack(s, pos, USET_SPAN_NOT_CONTAINED);
+if(pos==0) {
+return 0;  // Reached the start of the string.
+}
+// Check whether the current code point is in the original set,
+// without the string starts and ends.
+int32_t cpLength=spanOneBack(spanSet, s, pos);
+if(cpLength>0) {
+return pos;  // There is a set element at pos.
+}
+// Try to match the strings at pos.
+for(i=0; i<stringsLength; ++i) {
+// Use spanLengths rather than a spanBackLengths pointer because
+// it is easier and we only need to know whether the string is irrelevant
+// which is the same in either array.
+if(spanLengths[i]==ALL_CP_CONTAINED) {
+continue;  // Irrelevant string.
+}
+const UnicodeString &string=*(const UnicodeString *)strings.elementAt(i);
+const UChar *s16=string.getBuffer();
+int32_t length16=string.length();
+if(length16<=pos && matches16CPB(s, pos-length16, length, s16, length16)) {
+return pos;  // There is a set element at pos.
+}
+}
+// The span(while not contained) ended on a string start/end which is
+// not in the original set. Skip this code point and continue.
+// cpLength<0
+pos+=cpLength;
+} while(pos!=0);
+return 0;  // Reached the start of the string.
+}
+int32_t UnicodeSetStringSpan::spanNotUTF8(const uint8_t *s, int32_t length) const {
+int32_t pos=0, rest=length;
+int32_t i, stringsLength=strings.size();
+uint8_t *spanUTF8Lengths=spanLengths;
+if(all) {
+spanUTF8Lengths+=2*stringsLength;
+}
+do {
+// Span until we find a code point from the set,
+// or a code point that starts or ends some string.
+i=pSpanNotSet->spanUTF8((const char *)s+pos, rest, USET_SPAN_NOT_CONTAINED);
+if(i==rest) {
+return length;  // Reached the end of the string.
+}
+pos+=i;
+rest-=i;
+// Check whether the current code point is in the original set,
+// without the string starts and ends.
+int32_t cpLength=spanOneUTF8(spanSet, s+pos, rest);
+if(cpLength>0) {
+return pos;  // There is a set element at pos.
+}
+// Try to match the strings at pos.
+const uint8_t *s8=utf8;
+int32_t length8;
+for(i=0; i<stringsLength; ++i) {
+length8=utf8Lengths[i];
+// ALL_CP_CONTAINED: Irrelevant string.
+if(length8!=0 && spanUTF8Lengths[i]!=ALL_CP_CONTAINED && length8<=rest && matches8(s+pos, s8, length8)) {
+return pos;  // There is a set element at pos.
+}
+s8+=length8;
+}
+// The span(while not contained) ended on a string start/end which is
+// not in the original set. Skip this code point and continue.
+// cpLength<0
+pos-=cpLength;
+rest+=cpLength;
+} while(rest!=0);
+return length;  // Reached the end of the string.
+}
+int32_t UnicodeSetStringSpan::spanNotBackUTF8(const uint8_t *s, int32_t length) const {
+int32_t pos=length;
+int32_t i, stringsLength=strings.size();
+uint8_t *spanBackUTF8Lengths=spanLengths;
+if(all) {
+spanBackUTF8Lengths+=3*stringsLength;
+}
+do {
+// Span until we find a code point from the set,
+// or a code point that starts or ends some string.
+pos=pSpanNotSet->spanBackUTF8((const char *)s, pos, USET_SPAN_NOT_CONTAINED);
+if(pos==0) {
+return 0;  // Reached the start of the string.
+}
+// Check whether the current code point is in the original set,
+// without the string starts and ends.
+int32_t cpLength=spanOneBackUTF8(spanSet, s, pos);
+if(cpLength>0) {
+return pos;  // There is a set element at pos.
+}
+// Try to match the strings at pos.
+const uint8_t *s8=utf8;
+int32_t length8;
+for(i=0; i<stringsLength; ++i) {
+length8=utf8Lengths[i];
+// ALL_CP_CONTAINED: Irrelevant string.
+if(length8!=0 && spanBackUTF8Lengths[i]!=ALL_CP_CONTAINED && length8<=pos && matches8(s+pos-length8, s8, length8)) {
+return pos;  // There is a set element at pos.
+}
+s8+=length8;
+}
+// The span(while not contained) ended on a string start/end which is
+// not in the original set. Skip this code point and continue.
+// cpLength<0
+pos+=cpLength;
+} while(pos!=0);
+return 0;  // Reached the start of the string.
+}
+U_NAMESPACE_END

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comparison: intl/icu/source/common/unisetspan.cpp

intl/icu/source/common/unisetspan.cpp