Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1980 insertions, 0 deletions

diff --git a/intl/icu/source/i18n/uregex.cpp b/intl/icu/source/i18n/uregex.cpp
new file mode 100644
index 0000000000..7f41918cff
--- /dev/null
+++ b/intl/icu/source/i18n/uregex.cpp
@@ -0,0 +1,1980 @@
+// © 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+/*
+*******************************************************************************
+*   Copyright (C) 2004-2015, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+*******************************************************************************
+*   file name:  uregex.cpp
+*/
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_REGULAR_EXPRESSIONS
+
+#include "unicode/regex.h"
+#include "unicode/uregex.h"
+#include "unicode/unistr.h"
+#include "unicode/ustring.h"
+#include "unicode/uchar.h"
+#include "unicode/uobject.h"
+#include "unicode/utf16.h"
+#include "cmemory.h"
+#include "uassert.h"
+#include "uhash.h"
+#include "umutex.h"
+#include "uvectr32.h"
+
+#include "regextxt.h"
+
+U_NAMESPACE_BEGIN
+
+#define REMAINING_CAPACITY(idx,len) ((((len)-(idx))>0)?((len)-(idx)):0)
+
+struct RegularExpression: public UMemory {
+public:
+    RegularExpression();
+    ~RegularExpression();
+    int32_t           fMagic;
+    RegexPattern     *fPat;
+    u_atomic_int32_t *fPatRefCount;
+    UChar            *fPatString;
+    int32_t           fPatStringLen;
+    RegexMatcher     *fMatcher;
+    const UChar      *fText;         // Text from setText()
+    int32_t           fTextLength;   // Length provided by user with setText(), which
+                                     //  may be -1.
+    UBool             fOwnsText;
+};
+
+static const int32_t REXP_MAGIC = 0x72657870; // "rexp" in ASCII
+
+RegularExpression::RegularExpression() {
+    fMagic        = REXP_MAGIC;
+    fPat          = NULL;
+    fPatRefCount  = NULL;
+    fPatString    = NULL;
+    fPatStringLen = 0;
+    fMatcher      = NULL;
+    fText         = NULL;
+    fTextLength   = 0;
+    fOwnsText     = FALSE;
+}
+
+RegularExpression::~RegularExpression() {
+    delete fMatcher;
+    fMatcher = NULL;
+    if (fPatRefCount!=NULL && umtx_atomic_dec(fPatRefCount)==0) {
+        delete fPat;
+        uprv_free(fPatString);
+        uprv_free((void *)fPatRefCount);
+    }
+    if (fOwnsText && fText!=NULL) {
+        uprv_free((void *)fText);
+    }
+    fMagic = 0;
+}
+
+U_NAMESPACE_END
+
+U_NAMESPACE_USE
+
+//----------------------------------------------------------------------------------------
+//
+//   validateRE    Do boilerplate style checks on API function parameters.
+//                 Return TRUE if they look OK.
+//----------------------------------------------------------------------------------------
+static UBool validateRE(const RegularExpression *re, UBool requiresText, UErrorCode *status) {
+    if (U_FAILURE(*status)) {
+        return FALSE;
+    }
+    if (re == NULL || re->fMagic != REXP_MAGIC) {
+        *status = U_ILLEGAL_ARGUMENT_ERROR;
+        return FALSE;
+    }
+    // !!! Not sure how to update this with the new UText backing, which is stored in re->fMatcher anyway
+    if (requiresText && re->fText == NULL && !re->fOwnsText) {
+        *status = U_REGEX_INVALID_STATE;
+        return FALSE;
+    }
+    return TRUE;
+}
+
+//----------------------------------------------------------------------------------------
+//
+//    uregex_open
+//
+//----------------------------------------------------------------------------------------
+U_CAPI URegularExpression *  U_EXPORT2
+uregex_open( const  UChar          *pattern,
+                    int32_t         patternLength,
+                    uint32_t        flags,
+                    UParseError    *pe,
+                    UErrorCode     *status) {
+
+    if (U_FAILURE(*status)) {
+        return NULL;
+    }
+    if (pattern == NULL || patternLength < -1 || patternLength == 0) {
+        *status = U_ILLEGAL_ARGUMENT_ERROR;
+        return NULL;
+    }
+    int32_t actualPatLen = patternLength;
+    if (actualPatLen == -1) {
+        actualPatLen = u_strlen(pattern);
+    }
+
+    RegularExpression  *re     = new RegularExpression;
+    u_atomic_int32_t   *refC   = (u_atomic_int32_t *)uprv_malloc(sizeof(int32_t));
+    UChar              *patBuf = (UChar *)uprv_malloc(sizeof(UChar)*(actualPatLen+1));
+    if (re == NULL || refC == NULL || patBuf == NULL) {
+        *status = U_MEMORY_ALLOCATION_ERROR;
+        delete re;
+        uprv_free((void *)refC);
+        uprv_free(patBuf);
+        return NULL;
+    }
+    re->fPatRefCount = refC;
+    *re->fPatRefCount = 1;
+
+    //
+    // Make a copy of the pattern string, so we can return it later if asked.
+    //    For compiling the pattern, we will use a UText wrapper around
+    //    this local copy, to avoid making even more copies.
+    //
+    re->fPatString    = patBuf;
+    re->fPatStringLen = patternLength;
+    u_memcpy(patBuf, pattern, actualPatLen);
+    patBuf[actualPatLen] = 0;
+
+    UText patText = UTEXT_INITIALIZER;
+    utext_openUChars(&patText, patBuf, patternLength, status);
+
+    //
+    // Compile the pattern
+    //
+    if (pe != NULL) {
+        re->fPat = RegexPattern::compile(&patText, flags, *pe, *status);
+    } else {
+        re->fPat = RegexPattern::compile(&patText, flags, *status);
+    }
+    utext_close(&patText);
+
+    if (U_FAILURE(*status)) {
+        goto ErrorExit;
+    }
+
+    //
+    // Create the matcher object
+    //
+    re->fMatcher = re->fPat->matcher(*status);
+    if (U_SUCCESS(*status)) {
+        return (URegularExpression*)re;
+    }
+
+ErrorExit:
+    delete re;
+    return NULL;
+
+}
+
+//----------------------------------------------------------------------------------------
+//
+//    uregex_openUText
+//
+//----------------------------------------------------------------------------------------
+U_CAPI URegularExpression *  U_EXPORT2
+uregex_openUText(UText          *pattern,
+                 uint32_t        flags,
+                 UParseError    *pe,
+                 UErrorCode     *status) {
+
+    if (U_FAILURE(*status)) {
+        return NULL;
+    }
+    if (pattern == NULL) {
+        *status = U_ILLEGAL_ARGUMENT_ERROR;
+        return NULL;
+    }
+
+    int64_t patternNativeLength = utext_nativeLength(pattern);
+
+    if (patternNativeLength == 0) {
+        *status = U_ILLEGAL_ARGUMENT_ERROR;
+        return NULL;
+    }
+
+    RegularExpression *re     = new RegularExpression;
+
+    UErrorCode lengthStatus = U_ZERO_ERROR;
+    int32_t pattern16Length = utext_extract(pattern, 0, patternNativeLength, NULL, 0, &lengthStatus);
+
+    u_atomic_int32_t   *refC   = (u_atomic_int32_t *)uprv_malloc(sizeof(int32_t));
+    UChar              *patBuf = (UChar *)uprv_malloc(sizeof(UChar)*(pattern16Length+1));
+    if (re == NULL || refC == NULL || patBuf == NULL) {
+        *status = U_MEMORY_ALLOCATION_ERROR;
+        delete re;
+        uprv_free((void *)refC);
+        uprv_free(patBuf);
+        return NULL;
+    }
+    re->fPatRefCount = refC;
+    *re->fPatRefCount = 1;
+
+    //
+    // Make a copy of the pattern string, so we can return it later if asked.
+    //    For compiling the pattern, we will use a read-only UText wrapper
+    //    around this local copy, to avoid making even more copies.
+    //
+    re->fPatString    = patBuf;
+    re->fPatStringLen = pattern16Length;
+    utext_extract(pattern, 0, patternNativeLength, patBuf, pattern16Length+1, status);
+
+    UText patText = UTEXT_INITIALIZER;
+    utext_openUChars(&patText, patBuf, pattern16Length, status);
+
+    //
+    // Compile the pattern
+    //
+    if (pe != NULL) {
+        re->fPat = RegexPattern::compile(&patText, flags, *pe, *status);
+    } else {
+        re->fPat = RegexPattern::compile(&patText, flags, *status);
+    }
+    utext_close(&patText);
+
+    if (U_FAILURE(*status)) {
+        goto ErrorExit;
+    }
+
+    //
+    // Create the matcher object
+    //
+    re->fMatcher = re->fPat->matcher(*status);
+    if (U_SUCCESS(*status)) {
+        return (URegularExpression*)re;
+    }
+
+ErrorExit:
+    delete re;
+    return NULL;
+
+}
+
+//----------------------------------------------------------------------------------------
+//
+//    uregex_close
+//
+//----------------------------------------------------------------------------------------
+U_CAPI void  U_EXPORT2
+uregex_close(URegularExpression  *re2) {
+    RegularExpression *re = (RegularExpression*)re2;
+    UErrorCode  status = U_ZERO_ERROR;
+    if (validateRE(re, FALSE, &status) == FALSE) {
+        return;
+    }
+    delete re;
+}
+
+
+//----------------------------------------------------------------------------------------
+//
+//    uregex_clone
+//
+//----------------------------------------------------------------------------------------
+U_CAPI URegularExpression * U_EXPORT2
+uregex_clone(const URegularExpression *source2, UErrorCode *status)  {
+    RegularExpression *source = (RegularExpression*)source2;
+    if (validateRE(source, FALSE, status) == FALSE) {
+        return NULL;
+    }
+
+    RegularExpression *clone = new RegularExpression;
+    if (clone == NULL) {
+        *status = U_MEMORY_ALLOCATION_ERROR;
+        return NULL;
+    }
+
+    clone->fMatcher = source->fPat->matcher(*status);
+    if (U_FAILURE(*status)) {
+        delete clone;
+        return NULL;
+    }
+
+    clone->fPat          = source->fPat;
+    clone->fPatRefCount  = source->fPatRefCount;
+    clone->fPatString    = source->fPatString;
+    clone->fPatStringLen = source->fPatStringLen;
+    umtx_atomic_inc(source->fPatRefCount);
+    // Note:  fText is not cloned.
+
+    return (URegularExpression*)clone;
+}
+
+
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_pattern
+//
+//------------------------------------------------------------------------------
+U_CAPI const UChar * U_EXPORT2
+uregex_pattern(const  URegularExpression *regexp2,
+                      int32_t            *patLength,
+                      UErrorCode         *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+
+    if (validateRE(regexp, FALSE, status) == FALSE) {
+        return NULL;
+    }
+    if (patLength != NULL) {
+        *patLength = regexp->fPatStringLen;
+    }
+    return regexp->fPatString;
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_patternUText
+//
+//------------------------------------------------------------------------------
+U_CAPI UText * U_EXPORT2
+uregex_patternUText(const URegularExpression *regexp2,
+                          UErrorCode         *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    return regexp->fPat->patternText(*status);
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_flags
+//
+//------------------------------------------------------------------------------
+U_CAPI int32_t U_EXPORT2
+uregex_flags(const URegularExpression *regexp2, UErrorCode *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, FALSE, status) == FALSE) {
+        return 0;
+    }
+    int32_t flags = regexp->fPat->flags();
+    return flags;
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_setText
+//
+//------------------------------------------------------------------------------
+U_CAPI void U_EXPORT2
+uregex_setText(URegularExpression *regexp2,
+               const UChar        *text,
+               int32_t             textLength,
+               UErrorCode         *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, FALSE, status) == FALSE) {
+        return;
+    }
+    if (text == NULL || textLength < -1) {
+        *status = U_ILLEGAL_ARGUMENT_ERROR;
+        return;
+    }
+
+    if (regexp->fOwnsText && regexp->fText != NULL) {
+        uprv_free((void *)regexp->fText);
+    }
+
+    regexp->fText       = text;
+    regexp->fTextLength = textLength;
+    regexp->fOwnsText   = FALSE;
+
+    UText input = UTEXT_INITIALIZER;
+    utext_openUChars(&input, text, textLength, status);
+    regexp->fMatcher->reset(&input);
+    utext_close(&input); // reset() made a shallow clone, so we don't need this copy
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_setUText
+//
+//------------------------------------------------------------------------------
+U_CAPI void U_EXPORT2
+uregex_setUText(URegularExpression *regexp2,
+                UText              *text,
+                UErrorCode         *status) {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, FALSE, status) == FALSE) {
+        return;
+    }
+    if (text == NULL) {
+        *status = U_ILLEGAL_ARGUMENT_ERROR;
+        return;
+    }
+
+    if (regexp->fOwnsText && regexp->fText != NULL) {
+        uprv_free((void *)regexp->fText);
+    }
+
+    regexp->fText       = NULL; // only fill it in on request
+    regexp->fTextLength = -1;
+    regexp->fOwnsText   = TRUE;
+    regexp->fMatcher->reset(text);
+}
+
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_getText
+//
+//------------------------------------------------------------------------------
+U_CAPI const UChar * U_EXPORT2
+uregex_getText(URegularExpression *regexp2,
+               int32_t            *textLength,
+               UErrorCode         *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, FALSE, status) == FALSE) {
+        return NULL;
+    }
+
+    if (regexp->fText == NULL) {
+        // need to fill in the text
+        UText *inputText = regexp->fMatcher->inputText();
+        int64_t inputNativeLength = utext_nativeLength(inputText);
+        if (UTEXT_FULL_TEXT_IN_CHUNK(inputText, inputNativeLength)) {
+            regexp->fText = inputText->chunkContents;
+            regexp->fTextLength = (int32_t)inputNativeLength;
+            regexp->fOwnsText = FALSE; // because the UText owns it
+        } else {
+            UErrorCode lengthStatus = U_ZERO_ERROR;
+            regexp->fTextLength = utext_extract(inputText, 0, inputNativeLength, NULL, 0, &lengthStatus); // buffer overflow error
+            UChar *inputChars = (UChar *)uprv_malloc(sizeof(UChar)*(regexp->fTextLength+1));
+
+            utext_extract(inputText, 0, inputNativeLength, inputChars, regexp->fTextLength+1, status);
+            regexp->fText = inputChars;
+            regexp->fOwnsText = TRUE; // should already be set but just in case
+        }
+    }
+
+    if (textLength != NULL) {
+        *textLength = regexp->fTextLength;
+    }
+    return regexp->fText;
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_getUText
+//
+//------------------------------------------------------------------------------
+U_CAPI UText * U_EXPORT2
+uregex_getUText(URegularExpression *regexp2,
+                UText              *dest,
+                UErrorCode         *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, FALSE, status) == FALSE) {
+        return dest;
+    }
+    return regexp->fMatcher->getInput(dest, *status);
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_refreshUText
+//
+//------------------------------------------------------------------------------
+U_CAPI void U_EXPORT2
+uregex_refreshUText(URegularExpression *regexp2,
+                    UText              *text,
+                    UErrorCode         *status) {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, FALSE, status) == FALSE) {
+        return;
+    }
+    regexp->fMatcher->refreshInputText(text, *status);
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_matches
+//
+//------------------------------------------------------------------------------
+U_CAPI UBool U_EXPORT2
+uregex_matches(URegularExpression *regexp2,
+               int32_t            startIndex,
+               UErrorCode        *status)  {
+    return uregex_matches64( regexp2, (int64_t)startIndex, status);
+}
+
+U_CAPI UBool U_EXPORT2
+uregex_matches64(URegularExpression *regexp2,
+                 int64_t            startIndex,
+                 UErrorCode        *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    UBool result = FALSE;
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return result;
+    }
+    if (startIndex == -1) {
+        result = regexp->fMatcher->matches(*status);
+    } else {
+        result = regexp->fMatcher->matches(startIndex, *status);
+    }
+    return result;
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_lookingAt
+//
+//------------------------------------------------------------------------------
+U_CAPI UBool U_EXPORT2
+uregex_lookingAt(URegularExpression *regexp2,
+                 int32_t             startIndex,
+                 UErrorCode         *status)  {
+    return uregex_lookingAt64( regexp2, (int64_t)startIndex, status);
+}
+
+U_CAPI UBool U_EXPORT2
+uregex_lookingAt64(URegularExpression *regexp2,
+                   int64_t             startIndex,
+                   UErrorCode         *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    UBool result = FALSE;
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return result;
+    }
+    if (startIndex == -1) {
+        result = regexp->fMatcher->lookingAt(*status);
+    } else {
+        result = regexp->fMatcher->lookingAt(startIndex, *status);
+    }
+    return result;
+}
+
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_find
+//
+//------------------------------------------------------------------------------
+U_CAPI UBool U_EXPORT2
+uregex_find(URegularExpression *regexp2,
+            int32_t             startIndex,
+            UErrorCode         *status)  {
+    return uregex_find64( regexp2, (int64_t)startIndex, status);
+}
+
+U_CAPI UBool U_EXPORT2
+uregex_find64(URegularExpression *regexp2,
+              int64_t             startIndex,
+              UErrorCode         *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    UBool result = FALSE;
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return result;
+    }
+    if (startIndex == -1) {
+        regexp->fMatcher->resetPreserveRegion();
+        result = regexp->fMatcher->find(*status);
+    } else {
+        result = regexp->fMatcher->find(startIndex, *status);
+    }
+    return result;
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_findNext
+//
+//------------------------------------------------------------------------------
+U_CAPI UBool U_EXPORT2
+uregex_findNext(URegularExpression *regexp2,
+                UErrorCode         *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return FALSE;
+    }
+    UBool result = regexp->fMatcher->find(*status);
+    return result;
+}
+
+//------------------------------------------------------------------------------
+//
+//    uregex_groupCount
+//
+//------------------------------------------------------------------------------
+U_CAPI int32_t U_EXPORT2
+uregex_groupCount(URegularExpression *regexp2,
+                  UErrorCode         *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, FALSE, status) == FALSE) {
+        return 0;
+    }
+    int32_t  result = regexp->fMatcher->groupCount();
+    return result;
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_groupNumberFromName
+//
+//------------------------------------------------------------------------------
+int32_t
+uregex_groupNumberFromName(URegularExpression *regexp2,
+                           const UChar        *groupName,
+                           int32_t             nameLength,
+                           UErrorCode          *status) {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, FALSE, status) == FALSE) {
+        return 0;
+    }
+    int32_t  result = regexp->fPat->groupNumberFromName(UnicodeString(groupName, nameLength), *status);
+    return result;
+}
+
+int32_t
+uregex_groupNumberFromCName(URegularExpression *regexp2,
+                            const char         *groupName,
+                            int32_t             nameLength,
+                            UErrorCode          *status) {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, FALSE, status) == FALSE) {
+        return 0;
+    }
+    return regexp->fPat->groupNumberFromName(groupName, nameLength, *status);
+}
+
+//------------------------------------------------------------------------------
+//
+//    uregex_group
+//
+//------------------------------------------------------------------------------
+U_CAPI int32_t U_EXPORT2
+uregex_group(URegularExpression *regexp2,
+             int32_t             groupNum,
+             UChar              *dest,
+             int32_t             destCapacity,
+             UErrorCode          *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return 0;
+    }
+    if (destCapacity < 0 || (destCapacity > 0 && dest == NULL)) {
+        *status = U_ILLEGAL_ARGUMENT_ERROR;
+        return 0;
+    }
+
+    if (destCapacity == 0 || regexp->fText != NULL) {
+        // If preflighting or if we already have the text as UChars,
+        // this is a little cheaper than extracting from the UText
+
+        //
+        // Pick up the range of characters from the matcher
+        //
+        int32_t  startIx = regexp->fMatcher->start(groupNum, *status);
+        int32_t  endIx   = regexp->fMatcher->end  (groupNum, *status);
+        if (U_FAILURE(*status)) {
+            return 0;
+        }
+
+        //
+        // Trim length based on buffer capacity
+        //
+        int32_t fullLength = endIx - startIx;
+        int32_t copyLength = fullLength;
+        if (copyLength < destCapacity) {
+            dest[copyLength] = 0;
+        } else if (copyLength == destCapacity) {
+            *status = U_STRING_NOT_TERMINATED_WARNING;
+        } else {
+            copyLength = destCapacity;
+            *status = U_BUFFER_OVERFLOW_ERROR;
+        }
+
+        //
+        // Copy capture group to user's buffer
+        //
+        if (copyLength > 0) {
+            u_memcpy(dest, &regexp->fText[startIx], copyLength);
+        }
+        return fullLength;
+    } else {
+        int64_t  start = regexp->fMatcher->start64(groupNum, *status);
+        int64_t  limit = regexp->fMatcher->end64(groupNum, *status);
+        if (U_FAILURE(*status)) {
+            return 0;
+        }
+        // Note edge cases:
+        //   Group didn't match: start == end == -1. UText trims to 0, UText gives zero length result.
+        //   Zero Length Match: start == end.
+        int32_t length = utext_extract(regexp->fMatcher->inputText(), start, limit, dest, destCapacity, status);
+        return length;
+    }
+
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_groupUText
+//
+//------------------------------------------------------------------------------
+U_CAPI UText * U_EXPORT2
+uregex_groupUText(URegularExpression *regexp2,
+                  int32_t             groupNum,
+                  UText              *dest,
+                  int64_t            *groupLength,
+                  UErrorCode         *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        UErrorCode emptyTextStatus = U_ZERO_ERROR;
+        return (dest ? dest : utext_openUChars(NULL, NULL, 0, &emptyTextStatus));
+    }
+
+    return regexp->fMatcher->group(groupNum, dest, *groupLength, *status);
+}
+
+//------------------------------------------------------------------------------
+//
+//    uregex_start
+//
+//------------------------------------------------------------------------------
+U_CAPI int32_t U_EXPORT2
+uregex_start(URegularExpression *regexp2,
+             int32_t             groupNum,
+             UErrorCode          *status)  {
+    return (int32_t)uregex_start64( regexp2, groupNum, status);
+}
+
+U_CAPI int64_t U_EXPORT2
+uregex_start64(URegularExpression *regexp2,
+               int32_t             groupNum,
+               UErrorCode          *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return 0;
+    }
+    int64_t result = regexp->fMatcher->start64(groupNum, *status);
+    return result;
+}
+
+//------------------------------------------------------------------------------
+//
+//    uregex_end
+//
+//------------------------------------------------------------------------------
+U_CAPI int32_t U_EXPORT2
+uregex_end(URegularExpression   *regexp2,
+           int32_t               groupNum,
+           UErrorCode           *status)  {
+    return (int32_t)uregex_end64( regexp2, groupNum, status);
+}
+
+U_CAPI int64_t U_EXPORT2
+uregex_end64(URegularExpression   *regexp2,
+             int32_t               groupNum,
+             UErrorCode           *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return 0;
+    }
+    int64_t result = regexp->fMatcher->end64(groupNum, *status);
+    return result;
+}
+
+//------------------------------------------------------------------------------
+//
+//    uregex_reset
+//
+//------------------------------------------------------------------------------
+U_CAPI void U_EXPORT2
+uregex_reset(URegularExpression    *regexp2,
+             int32_t               index,
+             UErrorCode            *status)  {
+    uregex_reset64( regexp2, (int64_t)index, status);
+}
+
+U_CAPI void U_EXPORT2
+uregex_reset64(URegularExpression    *regexp2,
+               int64_t               index,
+               UErrorCode            *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return;
+    }
+    regexp->fMatcher->reset(index, *status);
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_setRegion
+//
+//------------------------------------------------------------------------------
+U_CAPI void U_EXPORT2
+uregex_setRegion(URegularExpression   *regexp2,
+                 int32_t               regionStart,
+                 int32_t               regionLimit,
+                 UErrorCode           *status)  {
+    uregex_setRegion64( regexp2, (int64_t)regionStart, (int64_t)regionLimit, status);
+}
+
+U_CAPI void U_EXPORT2
+uregex_setRegion64(URegularExpression   *regexp2,
+                   int64_t               regionStart,
+                   int64_t               regionLimit,
+                   UErrorCode           *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return;
+    }
+    regexp->fMatcher->region(regionStart, regionLimit, *status);
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_setRegionAndStart
+//
+//------------------------------------------------------------------------------
+U_CAPI void U_EXPORT2
+uregex_setRegionAndStart(URegularExpression   *regexp2,
+                 int64_t               regionStart,
+                 int64_t               regionLimit,
+                 int64_t               startIndex,
+                 UErrorCode           *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return;
+    }
+    regexp->fMatcher->region(regionStart, regionLimit, startIndex, *status);
+}
+
+//------------------------------------------------------------------------------
+//
+//    uregex_regionStart
+//
+//------------------------------------------------------------------------------
+U_CAPI int32_t U_EXPORT2
+uregex_regionStart(const  URegularExpression   *regexp2,
+                          UErrorCode           *status)  {
+    return (int32_t)uregex_regionStart64(regexp2, status);
+}
+
+U_CAPI int64_t U_EXPORT2
+uregex_regionStart64(const  URegularExpression   *regexp2,
+                            UErrorCode           *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return 0;
+    }
+    return regexp->fMatcher->regionStart();
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_regionEnd
+//
+//------------------------------------------------------------------------------
+U_CAPI int32_t U_EXPORT2
+uregex_regionEnd(const  URegularExpression   *regexp2,
+                        UErrorCode           *status)  {
+    return (int32_t)uregex_regionEnd64(regexp2, status);
+}
+
+U_CAPI int64_t U_EXPORT2
+uregex_regionEnd64(const  URegularExpression   *regexp2,
+                          UErrorCode           *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return 0;
+    }
+    return regexp->fMatcher->regionEnd();
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_hasTransparentBounds
+//
+//------------------------------------------------------------------------------
+U_CAPI UBool U_EXPORT2
+uregex_hasTransparentBounds(const  URegularExpression   *regexp2,
+                                   UErrorCode           *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, FALSE, status) == FALSE) {
+        return FALSE;
+    }
+    return regexp->fMatcher->hasTransparentBounds();
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_useTransparentBounds
+//
+//------------------------------------------------------------------------------
+U_CAPI void U_EXPORT2
+uregex_useTransparentBounds(URegularExpression    *regexp2,
+                            UBool                  b,
+                            UErrorCode            *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, FALSE, status) == FALSE) {
+        return;
+    }
+    regexp->fMatcher->useTransparentBounds(b);
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_hasAnchoringBounds
+//
+//------------------------------------------------------------------------------
+U_CAPI UBool U_EXPORT2
+uregex_hasAnchoringBounds(const  URegularExpression   *regexp2,
+                                 UErrorCode           *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, FALSE, status) == FALSE) {
+        return FALSE;
+    }
+    return regexp->fMatcher->hasAnchoringBounds();
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_useAnchoringBounds
+//
+//------------------------------------------------------------------------------
+U_CAPI void U_EXPORT2
+uregex_useAnchoringBounds(URegularExpression    *regexp2,
+                          UBool                  b,
+                          UErrorCode            *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, FALSE, status) == FALSE) {
+        return;
+    }
+    regexp->fMatcher->useAnchoringBounds(b);
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_hitEnd
+//
+//------------------------------------------------------------------------------
+U_CAPI UBool U_EXPORT2
+uregex_hitEnd(const  URegularExpression   *regexp2,
+                     UErrorCode           *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return FALSE;
+    }
+    return regexp->fMatcher->hitEnd();
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_requireEnd
+//
+//------------------------------------------------------------------------------
+U_CAPI UBool U_EXPORT2
+uregex_requireEnd(const  URegularExpression   *regexp2,
+                         UErrorCode           *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return FALSE;
+    }
+    return regexp->fMatcher->requireEnd();
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_setTimeLimit
+//
+//------------------------------------------------------------------------------
+U_CAPI void U_EXPORT2
+uregex_setTimeLimit(URegularExpression   *regexp2,
+                    int32_t               limit,
+                    UErrorCode           *status) {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, FALSE, status)) {
+        regexp->fMatcher->setTimeLimit(limit, *status);
+    }
+}
+
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_getTimeLimit
+//
+//------------------------------------------------------------------------------
+U_CAPI int32_t U_EXPORT2
+uregex_getTimeLimit(const  URegularExpression   *regexp2,
+                           UErrorCode           *status) {
+    int32_t retVal = 0;
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, FALSE, status)) {
+        retVal = regexp->fMatcher->getTimeLimit();
+    }
+    return retVal;
+}
+
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_setStackLimit
+//
+//------------------------------------------------------------------------------
+U_CAPI void U_EXPORT2
+uregex_setStackLimit(URegularExpression   *regexp2,
+                     int32_t               limit,
+                     UErrorCode           *status) {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, FALSE, status)) {
+        regexp->fMatcher->setStackLimit(limit, *status);
+    }
+}
+
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_getStackLimit
+//
+//------------------------------------------------------------------------------
+U_CAPI int32_t U_EXPORT2
+uregex_getStackLimit(const  URegularExpression   *regexp2,
+                            UErrorCode           *status) {
+    int32_t retVal = 0;
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, FALSE, status)) {
+        retVal = regexp->fMatcher->getStackLimit();
+    }
+    return retVal;
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_setMatchCallback
+//
+//------------------------------------------------------------------------------
+U_CAPI void U_EXPORT2
+uregex_setMatchCallback(URegularExpression      *regexp2,
+                        URegexMatchCallback     *callback,
+                        const void              *context,
+                        UErrorCode              *status) {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, FALSE, status)) {
+        regexp->fMatcher->setMatchCallback(callback, context, *status);
+    }
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_getMatchCallback
+//
+//------------------------------------------------------------------------------
+U_CAPI void U_EXPORT2
+uregex_getMatchCallback(const URegularExpression    *regexp2,
+                        URegexMatchCallback        **callback,
+                        const void                 **context,
+                        UErrorCode                  *status) {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+     if (validateRE(regexp, FALSE, status)) {
+         regexp->fMatcher->getMatchCallback(*callback, *context, *status);
+     }
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_setMatchProgressCallback
+//
+//------------------------------------------------------------------------------
+U_CAPI void U_EXPORT2
+uregex_setFindProgressCallback(URegularExpression              *regexp2,
+                                URegexFindProgressCallback      *callback,
+                                const void                      *context,
+                                UErrorCode                      *status) {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, FALSE, status)) {
+        regexp->fMatcher->setFindProgressCallback(callback, context, *status);
+    }
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_getMatchCallback
+//
+//------------------------------------------------------------------------------
+U_CAPI void U_EXPORT2
+uregex_getFindProgressCallback(const URegularExpression          *regexp2,
+                                URegexFindProgressCallback        **callback,
+                                const void                        **context,
+                                UErrorCode                        *status) {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+     if (validateRE(regexp, FALSE, status)) {
+         regexp->fMatcher->getFindProgressCallback(*callback, *context, *status);
+     }
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_replaceAll
+//
+//------------------------------------------------------------------------------
+U_CAPI int32_t U_EXPORT2
+uregex_replaceAll(URegularExpression    *regexp2,
+                  const UChar           *replacementText,
+                  int32_t                replacementLength,
+                  UChar                 *destBuf,
+                  int32_t                destCapacity,
+                  UErrorCode            *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return 0;
+    }
+    if (replacementText == NULL || replacementLength < -1 ||
+        (destBuf == NULL && destCapacity > 0) ||
+        destCapacity < 0) {
+        *status = U_ILLEGAL_ARGUMENT_ERROR;
+        return 0;
+    }
+
+    int32_t   len = 0;
+
+    uregex_reset(regexp2, 0, status);
+
+    // Note: Seperate error code variables for findNext() and appendReplacement()
+    //       are used so that destination buffer overflow errors
+    //       in appendReplacement won't stop findNext() from working.
+    //       appendReplacement() and appendTail() special case incoming buffer
+    //       overflow errors, continuing to return the correct length.
+    UErrorCode  findStatus = *status;
+    while (uregex_findNext(regexp2, &findStatus)) {
+        len += uregex_appendReplacement(regexp2, replacementText, replacementLength,
+                                        &destBuf, &destCapacity, status);
+    }
+    len += uregex_appendTail(regexp2, &destBuf, &destCapacity, status);
+
+    if (U_FAILURE(findStatus)) {
+        // If anything went wrong with the findNext(), make that error trump
+        //   whatever may have happened with the append() operations.
+        //   Errors in findNext() are not expected.
+        *status = findStatus;
+    }
+
+    return len;
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_replaceAllUText
+//
+//------------------------------------------------------------------------------
+U_CAPI UText * U_EXPORT2
+uregex_replaceAllUText(URegularExpression    *regexp2,
+                       UText                 *replacementText,
+                       UText                 *dest,
+                       UErrorCode            *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return 0;
+    }
+    if (replacementText == NULL) {
+        *status = U_ILLEGAL_ARGUMENT_ERROR;
+        return 0;
+    }
+
+    dest = regexp->fMatcher->replaceAll(replacementText, dest, *status);
+    return dest;
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_replaceFirst
+//
+//------------------------------------------------------------------------------
+U_CAPI int32_t U_EXPORT2
+uregex_replaceFirst(URegularExpression  *regexp2,
+                    const UChar         *replacementText,
+                    int32_t              replacementLength,
+                    UChar               *destBuf,
+                    int32_t              destCapacity,
+                    UErrorCode          *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return 0;
+    }
+    if (replacementText == NULL || replacementLength < -1 ||
+        (destBuf == NULL && destCapacity > 0) ||
+        destCapacity < 0) {
+        *status = U_ILLEGAL_ARGUMENT_ERROR;
+        return 0;
+    }
+
+    int32_t   len = 0;
+    UBool     findSucceeded;
+    uregex_reset(regexp2, 0, status);
+    findSucceeded = uregex_find(regexp2, 0, status);
+    if (findSucceeded) {
+        len = uregex_appendReplacement(regexp2, replacementText, replacementLength,
+                                       &destBuf, &destCapacity, status);
+    }
+    len += uregex_appendTail(regexp2, &destBuf, &destCapacity, status);
+
+    return len;
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_replaceFirstUText
+//
+//------------------------------------------------------------------------------
+U_CAPI UText * U_EXPORT2
+uregex_replaceFirstUText(URegularExpression  *regexp2,
+                         UText                 *replacementText,
+                         UText                 *dest,
+                         UErrorCode            *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return 0;
+    }
+    if (replacementText == NULL) {
+        *status = U_ILLEGAL_ARGUMENT_ERROR;
+        return 0;
+    }
+
+    dest = regexp->fMatcher->replaceFirst(replacementText, dest, *status);
+    return dest;
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_appendReplacement
+//
+//------------------------------------------------------------------------------
+
+U_NAMESPACE_BEGIN
+//
+//  Dummy class, because these functions need to be friends of class RegexMatcher,
+//               and stand-alone C functions don't work as friends
+//
+class RegexCImpl {
+ public:
+   inline static  int32_t appendReplacement(RegularExpression    *regexp,
+                      const UChar           *replacementText,
+                      int32_t                replacementLength,
+                      UChar                **destBuf,
+                      int32_t               *destCapacity,
+                      UErrorCode            *status);
+
+   inline static int32_t appendTail(RegularExpression    *regexp,
+        UChar                **destBuf,
+        int32_t               *destCapacity,
+        UErrorCode            *status);
+
+    inline static int32_t split(RegularExpression    *regexp,
+        UChar                 *destBuf,
+        int32_t                destCapacity,
+        int32_t               *requiredCapacity,
+        UChar                 *destFields[],
+        int32_t                destFieldsCapacity,
+        UErrorCode            *status);
+};
+
+U_NAMESPACE_END
+
+
+
+static const UChar BACKSLASH  = 0x5c;
+static const UChar DOLLARSIGN = 0x24;
+static const UChar LEFTBRACKET = 0x7b;
+static const UChar RIGHTBRACKET = 0x7d;
+
+//
+//  Move a character to an output buffer, with bounds checking on the index.
+//      Index advances even if capacity is exceeded, for preflight size computations.
+//      This little sequence is used a LOT.
+//
+static inline void appendToBuf(UChar c, int32_t *idx, UChar *buf, int32_t bufCapacity) {
+    if (*idx < bufCapacity) {
+        buf[*idx] = c;
+    }
+    (*idx)++;
+}
+
+
+//
+//  appendReplacement, the actual implementation.
+//
+int32_t RegexCImpl::appendReplacement(RegularExpression    *regexp,
+                                      const UChar           *replacementText,
+                                      int32_t                replacementLength,
+                                      UChar                **destBuf,
+                                      int32_t               *destCapacity,
+                                      UErrorCode            *status)  {
+
+    // If we come in with a buffer overflow error, don't suppress the operation.
+    //  A series of appendReplacements, appendTail need to correctly preflight
+    //  the buffer size when an overflow happens somewhere in the middle.
+    UBool pendingBufferOverflow = FALSE;
+    if (*status == U_BUFFER_OVERFLOW_ERROR && destCapacity != NULL && *destCapacity == 0) {
+        pendingBufferOverflow = TRUE;
+        *status = U_ZERO_ERROR;
+    }
+
+    //
+    // Validate all paramters
+    //
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return 0;
+    }
+    if (replacementText == NULL || replacementLength < -1 ||
+        destCapacity == NULL || destBuf == NULL ||
+        (*destBuf == NULL && *destCapacity > 0) ||
+        *destCapacity < 0) {
+        *status = U_ILLEGAL_ARGUMENT_ERROR;
+        return 0;
+    }
+
+    RegexMatcher *m = regexp->fMatcher;
+    if (m->fMatch == FALSE) {
+        *status = U_REGEX_INVALID_STATE;
+        return 0;
+    }
+
+    UChar    *dest             = *destBuf;
+    int32_t   capacity         = *destCapacity;
+    int32_t   destIdx          =  0;
+    int32_t   i;
+
+    // If it wasn't supplied by the caller,  get the length of the replacement text.
+    //   TODO:  slightly smarter logic in the copy loop could watch for the NUL on
+    //          the fly and avoid this step.
+    if (replacementLength == -1) {
+        replacementLength = u_strlen(replacementText);
+    }
+
+    // Copy input string from the end of previous match to start of current match
+    if (regexp->fText != NULL) {
+        int32_t matchStart;
+        int32_t lastMatchEnd;
+        if (UTEXT_USES_U16(m->fInputText)) {
+            lastMatchEnd = (int32_t)m->fLastMatchEnd;
+            matchStart = (int32_t)m->fMatchStart;
+        } else {
+            // !!!: Would like a better way to do this!
+            UErrorCode tempStatus = U_ZERO_ERROR;
+            lastMatchEnd = utext_extract(m->fInputText, 0, m->fLastMatchEnd, NULL, 0, &tempStatus);
+            tempStatus = U_ZERO_ERROR;
+            matchStart = lastMatchEnd + utext_extract(m->fInputText, m->fLastMatchEnd, m->fMatchStart, NULL, 0, &tempStatus);
+        }
+        for (i=lastMatchEnd; i<matchStart; i++) {
+            appendToBuf(regexp->fText[i], &destIdx, dest, capacity);
+        }
+    } else {
+        UErrorCode possibleOverflowError = U_ZERO_ERROR; // ignore
+        destIdx += utext_extract(m->fInputText, m->fLastMatchEnd, m->fMatchStart,
+                                 dest==NULL?NULL:&dest[destIdx], REMAINING_CAPACITY(destIdx, capacity),
+                                 &possibleOverflowError);
+    }
+    U_ASSERT(destIdx >= 0);
+
+    // scan the replacement text, looking for substitutions ($n) and \escapes.
+    int32_t  replIdx = 0;
+    while (replIdx < replacementLength && U_SUCCESS(*status)) {
+        UChar  c = replacementText[replIdx];
+        replIdx++;
+        if (c != DOLLARSIGN && c != BACKSLASH) {
+            // Common case, no substitution, no escaping,
+            //  just copy the char to the dest buf.
+            appendToBuf(c, &destIdx, dest, capacity);
+            continue;
+        }
+
+        if (c == BACKSLASH) {
+            // Backslash Escape.  Copy the following char out without further checks.
+            //                    Note:  Surrogate pairs don't need any special handling
+            //                           The second half wont be a '$' or a '\', and
+            //                           will move to the dest normally on the next
+            //                           loop iteration.
+            if (replIdx >= replacementLength) {
+                break;
+            }
+            c = replacementText[replIdx];
+
+            if (c==0x55/*U*/ || c==0x75/*u*/) {
+                // We have a \udddd or \Udddddddd escape sequence.
+                UChar32 escapedChar =
+                    u_unescapeAt(uregex_ucstr_unescape_charAt,
+                       &replIdx,                   // Index is updated by unescapeAt
+                       replacementLength,          // Length of replacement text
+                       (void *)replacementText);
+
+                if (escapedChar != (UChar32)0xFFFFFFFF) {
+                    if (escapedChar <= 0xffff) {
+                        appendToBuf((UChar)escapedChar, &destIdx, dest, capacity);
+                    } else {
+                        appendToBuf(U16_LEAD(escapedChar), &destIdx, dest, capacity);
+                        appendToBuf(U16_TRAIL(escapedChar), &destIdx, dest, capacity);
+                    }
+                    continue;
+                }
+                // Note:  if the \u escape was invalid, just fall through and
+                //        treat it as a plain \<anything> escape.
+            }
+
+            // Plain backslash escape.  Just put out the escaped character.
+            appendToBuf(c, &destIdx, dest, capacity);
+
+            replIdx++;
+            continue;
+        }
+
+        // We've got a $.  Pick up the following capture group name or number.
+        // For numbers, consume only digits that produce a valid capture group for the pattern.
+
+        int32_t groupNum  = 0;
+        U_ASSERT(c == DOLLARSIGN);
+        UChar32 c32 = -1;
+        if (replIdx < replacementLength) {
+            U16_GET(replacementText, 0, replIdx, replacementLength, c32);
+        }
+        if (u_isdigit(c32)) {
+            int32_t numDigits = 0;
+            int32_t numCaptureGroups = m->fPattern->fGroupMap->size();
+            for (;;) {
+                if (replIdx >= replacementLength) {
+                    break;
+                }
+                U16_GET(replacementText, 0, replIdx, replacementLength, c32);
+                if (u_isdigit(c32) == FALSE) {
+                    break;
+                }
+
+                int32_t digitVal = u_charDigitValue(c32);
+                if (groupNum * 10 + digitVal <= numCaptureGroups) {
+                    groupNum = groupNum * 10 + digitVal;
+                    U16_FWD_1(replacementText, replIdx, replacementLength);
+                    numDigits++;
+                } else {
+                    if (numDigits == 0) {
+                        *status = U_INDEX_OUTOFBOUNDS_ERROR;
+                    }
+                    break;
+                }
+            }
+        } else if (c32 == LEFTBRACKET) {
+            // Scan for Named Capture Group, ${name}.
+            UnicodeString groupName;
+            U16_FWD_1(replacementText, replIdx, replacementLength);
+            while (U_SUCCESS(*status) && c32 != RIGHTBRACKET) { 
+                if (replIdx >= replacementLength) {
+                    *status = U_REGEX_INVALID_CAPTURE_GROUP_NAME;
+                    break;
+                }
+                U16_NEXT(replacementText, replIdx, replacementLength, c32);
+                if ((c32 >= 0x41 && c32 <= 0x5a) ||           // A..Z
+                        (c32 >= 0x61 && c32 <= 0x7a) ||       // a..z
+                        (c32 >= 0x31 && c32 <= 0x39)) {       // 0..9
+                    groupName.append(c32);
+                } else if (c32 == RIGHTBRACKET) {
+                    groupNum = regexp->fPat->fNamedCaptureMap ?
+                            uhash_geti(regexp->fPat->fNamedCaptureMap, &groupName) : 0;
+                    if (groupNum == 0) {
+                        // Name not defined by pattern.
+                        *status = U_REGEX_INVALID_CAPTURE_GROUP_NAME;
+                    }
+                } else {
+                    // Character was something other than a name char or a closing '}'
+                    *status = U_REGEX_INVALID_CAPTURE_GROUP_NAME;
+                }
+            }
+        } else {
+            // $ not followed by {name} or digits.
+            *status = U_REGEX_INVALID_CAPTURE_GROUP_NAME;
+        }
+
+
+        // Finally, append the capture group data to the destination.
+        if (U_SUCCESS(*status)) {
+            destIdx += uregex_group((URegularExpression*)regexp, groupNum,
+                                    dest==NULL?NULL:&dest[destIdx], REMAINING_CAPACITY(destIdx, capacity), status);
+            if (*status == U_BUFFER_OVERFLOW_ERROR) {
+                // Ignore buffer overflow when extracting the group.  We need to
+                //   continue on to get full size of the untruncated result.  We will
+                //   raise our own buffer overflow error at the end.
+                *status = U_ZERO_ERROR;
+            }
+        }
+
+        if (U_FAILURE(*status)) {
+            // bad group number or name.
+            break;
+        }
+    }
+
+    //
+    //  Nul Terminate the dest buffer if possible.
+    //  Set the appropriate buffer overflow or not terminated error, if needed.
+    //
+    if (destIdx < capacity) {
+        dest[destIdx] = 0;
+    } else if (U_SUCCESS(*status)) {
+        if (destIdx == *destCapacity) {
+            *status = U_STRING_NOT_TERMINATED_WARNING;
+        } else {
+            *status = U_BUFFER_OVERFLOW_ERROR;
+        }
+    }
+
+    //
+    // Return an updated dest buffer and capacity to the caller.
+    //
+    if (destIdx > 0 &&  *destCapacity > 0) {
+        if (destIdx < capacity) {
+            *destBuf      += destIdx;
+            *destCapacity -= destIdx;
+        } else {
+            *destBuf      += capacity;
+            *destCapacity =  0;
+        }
+    }
+
+    // If we came in with a buffer overflow, make sure we go out with one also.
+    //   (A zero length match right at the end of the previous match could
+    //    make this function succeed even though a previous call had overflowed the buf)
+    if (pendingBufferOverflow && U_SUCCESS(*status)) {
+        *status = U_BUFFER_OVERFLOW_ERROR;
+    }
+
+    return destIdx;
+}
+
+//
+//   appendReplacement   the actual API function,
+//
+U_CAPI int32_t U_EXPORT2
+uregex_appendReplacement(URegularExpression    *regexp2,
+                         const UChar           *replacementText,
+                         int32_t                replacementLength,
+                         UChar                **destBuf,
+                         int32_t               *destCapacity,
+                         UErrorCode            *status) {
+
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    return RegexCImpl::appendReplacement(
+        regexp, replacementText, replacementLength,destBuf, destCapacity, status);
+}
+
+//
+//   uregex_appendReplacementUText...can just use the normal C++ method
+//
+U_CAPI void U_EXPORT2
+uregex_appendReplacementUText(URegularExpression    *regexp2,
+                              UText                 *replText,
+                              UText                 *dest,
+                              UErrorCode            *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    regexp->fMatcher->appendReplacement(dest, replText, *status);
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    uregex_appendTail
+//
+//------------------------------------------------------------------------------
+int32_t RegexCImpl::appendTail(RegularExpression    *regexp,
+                               UChar                **destBuf,
+                               int32_t               *destCapacity,
+                               UErrorCode            *status)
+{
+
+    // If we come in with a buffer overflow error, don't suppress the operation.
+    //  A series of appendReplacements, appendTail need to correctly preflight
+    //  the buffer size when an overflow happens somewhere in the middle.
+    UBool pendingBufferOverflow = FALSE;
+    if (*status == U_BUFFER_OVERFLOW_ERROR && destCapacity != NULL && *destCapacity == 0) {
+        pendingBufferOverflow = TRUE;
+        *status = U_ZERO_ERROR;
+    }
+
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return 0;
+    }
+
+    if (destCapacity == NULL || destBuf == NULL ||
+        (*destBuf == NULL && *destCapacity > 0) ||
+        *destCapacity < 0)
+    {
+        *status = U_ILLEGAL_ARGUMENT_ERROR;
+        return 0;
+    }
+
+    RegexMatcher *m = regexp->fMatcher;
+
+    int32_t  destIdx     = 0;
+    int32_t  destCap     = *destCapacity;
+    UChar    *dest       = *destBuf;
+
+    if (regexp->fText != NULL) {
+        int32_t srcIdx;
+        int64_t nativeIdx = (m->fMatch ? m->fMatchEnd : m->fLastMatchEnd);
+        if (nativeIdx == -1) {
+            srcIdx = 0;
+        } else if (UTEXT_USES_U16(m->fInputText)) {
+            srcIdx = (int32_t)nativeIdx;
+        } else {
+            UErrorCode newStatus = U_ZERO_ERROR;
+            srcIdx = utext_extract(m->fInputText, 0, nativeIdx, NULL, 0, &newStatus);
+        }
+
+        for (;;) {
+            U_ASSERT(destIdx >= 0);
+
+            if (srcIdx == regexp->fTextLength) {
+                break;
+            }
+            UChar c = regexp->fText[srcIdx];
+            if (c == 0 && regexp->fTextLength == -1) {
+                regexp->fTextLength = srcIdx;
+                break;
+            }
+
+            if (destIdx < destCap) {
+                dest[destIdx] = c;
+            } else {
+                // We've overflowed the dest buffer.
+                //  If the total input string length is known, we can
+                //    compute the total buffer size needed without scanning through the string.
+                if (regexp->fTextLength > 0) {
+                    destIdx += (regexp->fTextLength - srcIdx);
+                    break;
+                }
+            }
+            srcIdx++;
+            destIdx++;
+        }
+    } else {
+        int64_t  srcIdx;
+        if (m->fMatch) {
+            // The most recent call to find() succeeded.
+            srcIdx = m->fMatchEnd;
+        } else {
+            // The last call to find() on this matcher failed().
+            //   Look back to the end of the last find() that succeeded for src index.
+            srcIdx = m->fLastMatchEnd;
+            if (srcIdx == -1)  {
+                // There has been no successful match with this matcher.
+                //   We want to copy the whole string.
+                srcIdx = 0;
+            }
+        }
+
+        destIdx = utext_extract(m->fInputText, srcIdx, m->fInputLength, dest, destCap, status);
+    }
+
+    //
+    //  NUL terminate the output string, if possible, otherwise issue the
+    //   appropriate error or warning.
+    //
+    if (destIdx < destCap) {
+        dest[destIdx] = 0;
+    } else  if (destIdx == destCap) {
+        *status = U_STRING_NOT_TERMINATED_WARNING;
+    } else {
+        *status = U_BUFFER_OVERFLOW_ERROR;
+    }
+
+    //
+    // Update the user's buffer ptr and capacity vars to reflect the
+    //   amount used.
+    //
+    if (destIdx < destCap) {
+        *destBuf      += destIdx;
+        *destCapacity -= destIdx;
+    } else if (*destBuf != NULL) {
+        *destBuf      += destCap;
+        *destCapacity  = 0;
+    }
+
+    if (pendingBufferOverflow && U_SUCCESS(*status)) {
+        *status = U_BUFFER_OVERFLOW_ERROR;
+    }
+
+    return destIdx;
+}
+
+
+//
+//   appendTail   the actual API function
+//
+U_CAPI int32_t U_EXPORT2
+uregex_appendTail(URegularExpression    *regexp2,
+                  UChar                **destBuf,
+                  int32_t               *destCapacity,
+                  UErrorCode            *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    return RegexCImpl::appendTail(regexp, destBuf, destCapacity, status);
+}
+
+
+//
+//   uregex_appendTailUText...can just use the normal C++ method
+//
+U_CAPI UText * U_EXPORT2
+uregex_appendTailUText(URegularExpression    *regexp2,
+                       UText                 *dest,
+                       UErrorCode            *status)  {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    return regexp->fMatcher->appendTail(dest, *status);
+}
+
+
+//------------------------------------------------------------------------------
+//
+//    copyString     Internal utility to copy a string to an output buffer,
+//                   while managing buffer overflow and preflight size
+//                   computation.  NUL termination is added to destination,
+//                   and the NUL is counted in the output size.
+//
+//------------------------------------------------------------------------------
+#if 0
+static void copyString(UChar        *destBuffer,    //  Destination buffer.
+                       int32_t       destCapacity,  //  Total capacity of dest buffer
+                       int32_t      *destIndex,     //  Index into dest buffer.  Updated on return.
+                                                    //    Update not clipped to destCapacity.
+                       const UChar  *srcPtr,        //  Pointer to source string
+                       int32_t       srcLen)        //  Source string len.
+{
+    int32_t  si;
+    int32_t  di = *destIndex;
+    UChar    c;
+
+    for (si=0; si<srcLen;  si++) {
+        c = srcPtr[si];
+        if (di < destCapacity) {
+            destBuffer[di] = c;
+            di++;
+        } else {
+            di += srcLen - si;
+            break;
+        }
+    }
+    if (di<destCapacity) {
+        destBuffer[di] = 0;
+    }
+    di++;
+    *destIndex = di;
+}
+#endif
+
+//------------------------------------------------------------------------------
+//
+//    uregex_split
+//
+//------------------------------------------------------------------------------
+int32_t RegexCImpl::split(RegularExpression     *regexp,
+                          UChar                 *destBuf,
+                          int32_t                destCapacity,
+                          int32_t               *requiredCapacity,
+                          UChar                 *destFields[],
+                          int32_t                destFieldsCapacity,
+                          UErrorCode            *status) {
+    //
+    // Reset for the input text
+    //
+    regexp->fMatcher->reset();
+    UText *inputText = regexp->fMatcher->fInputText;
+    int64_t   nextOutputStringStart = 0;
+    int64_t   inputLen = regexp->fMatcher->fInputLength;
+    if (inputLen == 0) {
+        return 0;
+    }
+
+    //
+    // Loop through the input text, searching for the delimiter pattern
+    //
+    int32_t   i;             // Index of the field being processed.
+    int32_t   destIdx = 0;   // Next available position in destBuf;
+    int32_t   numCaptureGroups = regexp->fMatcher->groupCount();
+    UErrorCode  tStatus = U_ZERO_ERROR;   // Want to ignore any buffer overflow errors so that the strings are still counted
+    for (i=0; ; i++) {
+        if (i>=destFieldsCapacity-1) {
+            // There are one or zero output strings left.
+            // Fill the last output string with whatever is left from the input, then exit the loop.
+            //  ( i will be == destFieldsCapacity if we filled the output array while processing
+            //    capture groups of the delimiter expression, in which case we will discard the
+            //    last capture group saved in favor of the unprocessed remainder of the
+            //    input string.)
+            if (inputLen > nextOutputStringStart) {
+                if (i != destFieldsCapacity-1) {
+                    // No fields are left.  Recycle the last one for holding the trailing part of
+                    //   the input string.
+                    i = destFieldsCapacity-1;
+                    destIdx = (int32_t)(destFields[i] - destFields[0]);
+                }
+
+                destFields[i] = &destBuf[destIdx];
+                destIdx += 1 + utext_extract(inputText, nextOutputStringStart, inputLen,
+                                             &destBuf[destIdx], REMAINING_CAPACITY(destIdx, destCapacity), status);
+            }
+            break;
+        }
+
+        if (regexp->fMatcher->find()) {
+            // We found another delimiter.  Move everything from where we started looking
+            //  up until the start of the delimiter into the next output string.
+            destFields[i] = &destBuf[destIdx];
+
+            destIdx += 1 + utext_extract(inputText, nextOutputStringStart, regexp->fMatcher->fMatchStart,
+                                         &destBuf[destIdx], REMAINING_CAPACITY(destIdx, destCapacity), &tStatus);
+            if (tStatus == U_BUFFER_OVERFLOW_ERROR) {
+                tStatus = U_ZERO_ERROR;
+            } else {
+                *status = tStatus;
+            }
+            nextOutputStringStart = regexp->fMatcher->fMatchEnd;
+
+            // If the delimiter pattern has capturing parentheses, the captured
+            //  text goes out into the next n destination strings.
+            int32_t groupNum;
+            for (groupNum=1; groupNum<=numCaptureGroups; groupNum++) {
+                // If we've run out of output string slots, bail out.
+                if (i==destFieldsCapacity-1) {
+                    break;
+                }
+                i++;
+
+                // Set up to extract the capture group contents into the dest buffer.
+                destFields[i] = &destBuf[destIdx];
+                tStatus = U_ZERO_ERROR;
+                int32_t t = uregex_group((URegularExpression*)regexp,
+                                         groupNum,
+                                         destFields[i],
+                                         REMAINING_CAPACITY(destIdx, destCapacity),
+                                         &tStatus);
+                destIdx += t + 1;    // Record the space used in the output string buffer.
+                                     //  +1 for the NUL that terminates the string.
+                if (tStatus == U_BUFFER_OVERFLOW_ERROR) {
+                    tStatus = U_ZERO_ERROR;
+                } else {
+                    *status = tStatus;
+                }
+            }
+
+            if (nextOutputStringStart == inputLen) {
+                // The delimiter was at the end of the string.
+                // Output an empty string, and then we are done.
+                if (destIdx < destCapacity) {
+                    destBuf[destIdx] = 0;
+                }
+                if (i < destFieldsCapacity-1) {
+                   ++i;
+                }
+                if (destIdx < destCapacity) {
+                    destFields[i] = destBuf + destIdx;
+                }
+                ++destIdx;
+                break;
+            }
+
+        }
+        else
+        {
+            // We ran off the end of the input while looking for the next delimiter.
+            // All the remaining text goes into the current output string.
+            destFields[i] = &destBuf[destIdx];
+            destIdx += 1 + utext_extract(inputText, nextOutputStringStart, inputLen,
+                                         &destBuf[destIdx], REMAINING_CAPACITY(destIdx, destCapacity), status);
+            break;
+        }
+    }
+
+    // Zero out any unused portion of the destFields array
+    int j;
+    for (j=i+1; j<destFieldsCapacity; j++) {
+        destFields[j] = NULL;
+    }
+
+    if (requiredCapacity != NULL) {
+        *requiredCapacity = destIdx;
+    }
+    if (destIdx > destCapacity) {
+        *status = U_BUFFER_OVERFLOW_ERROR;
+    }
+    return i+1;
+}
+
+//
+//   uregex_split   The actual API function
+//
+U_CAPI int32_t U_EXPORT2
+uregex_split(URegularExpression      *regexp2,
+             UChar                   *destBuf,
+             int32_t                  destCapacity,
+             int32_t                 *requiredCapacity,
+             UChar                   *destFields[],
+             int32_t                  destFieldsCapacity,
+             UErrorCode              *status) {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    if (validateRE(regexp, TRUE, status) == FALSE) {
+        return 0;
+    }
+    if ((destBuf == NULL && destCapacity > 0) ||
+        destCapacity < 0 ||
+        destFields == NULL ||
+        destFieldsCapacity < 1 ) {
+        *status = U_ILLEGAL_ARGUMENT_ERROR;
+        return 0;
+    }
+
+    return RegexCImpl::split(regexp, destBuf, destCapacity, requiredCapacity, destFields, destFieldsCapacity, status);
+}
+
+
+//
+//   uregex_splitUText...can just use the normal C++ method
+//
+U_CAPI int32_t U_EXPORT2
+uregex_splitUText(URegularExpression    *regexp2,
+                  UText                 *destFields[],
+                  int32_t                destFieldsCapacity,
+                  UErrorCode            *status) {
+    RegularExpression *regexp = (RegularExpression*)regexp2;
+    return regexp->fMatcher->split(regexp->fMatcher->inputText(), destFields, destFieldsCapacity, *status);
+}
+
+
+#endif   // !UCONFIG_NO_REGULAR_EXPRESSIONS
+