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scuffed-code/common/caniter.cpp

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// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*****************************************************************************
* Copyright (C) 1996-2015, International Business Machines Corporation and
* others. All Rights Reserved.
*****************************************************************************
*/
#include "unicode/utypes.h"
#if !UCONFIG_NO_NORMALIZATION
#include "unicode/caniter.h"
#include "unicode/normalizer2.h"
#include "unicode/uchar.h"
#include "unicode/uniset.h"
#include "unicode/usetiter.h"
#include "unicode/ustring.h"
#include "unicode/utf16.h"
#include "cmemory.h"
#include "hash.h"
#include "normalizer2impl.h"
/**
* This class allows one to iterate through all the strings that are canonically equivalent to a given
* string. For example, here are some sample results:
Results for: {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D}{COMBINING DOT ABOVE}{COMBINING CEDILLA}
1: \u0041\u030A\u0064\u0307\u0327
= {LATIN CAPITAL LETTER A}{COMBINING RING ABOVE}{LATIN SMALL LETTER D}{COMBINING DOT ABOVE}{COMBINING CEDILLA}
2: \u0041\u030A\u0064\u0327\u0307
= {LATIN CAPITAL LETTER A}{COMBINING RING ABOVE}{LATIN SMALL LETTER D}{COMBINING CEDILLA}{COMBINING DOT ABOVE}
3: \u0041\u030A\u1E0B\u0327
= {LATIN CAPITAL LETTER A}{COMBINING RING ABOVE}{LATIN SMALL LETTER D WITH DOT ABOVE}{COMBINING CEDILLA}
4: \u0041\u030A\u1E11\u0307
= {LATIN CAPITAL LETTER A}{COMBINING RING ABOVE}{LATIN SMALL LETTER D WITH CEDILLA}{COMBINING DOT ABOVE}
5: \u00C5\u0064\u0307\u0327
= {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D}{COMBINING DOT ABOVE}{COMBINING CEDILLA}
6: \u00C5\u0064\u0327\u0307
= {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D}{COMBINING CEDILLA}{COMBINING DOT ABOVE}
7: \u00C5\u1E0B\u0327
= {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D WITH DOT ABOVE}{COMBINING CEDILLA}
8: \u00C5\u1E11\u0307
= {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D WITH CEDILLA}{COMBINING DOT ABOVE}
9: \u212B\u0064\u0307\u0327
= {ANGSTROM SIGN}{LATIN SMALL LETTER D}{COMBINING DOT ABOVE}{COMBINING CEDILLA}
10: \u212B\u0064\u0327\u0307
= {ANGSTROM SIGN}{LATIN SMALL LETTER D}{COMBINING CEDILLA}{COMBINING DOT ABOVE}
11: \u212B\u1E0B\u0327
= {ANGSTROM SIGN}{LATIN SMALL LETTER D WITH DOT ABOVE}{COMBINING CEDILLA}
12: \u212B\u1E11\u0307
= {ANGSTROM SIGN}{LATIN SMALL LETTER D WITH CEDILLA}{COMBINING DOT ABOVE}
*<br>Note: the code is intended for use with small strings, and is not suitable for larger ones,
* since it has not been optimized for that situation.
*@author M. Davis
*@draft
*/
// public
U_NAMESPACE_BEGIN
// TODO: add boilerplate methods.
UOBJECT_DEFINE_RTTI_IMPLEMENTATION(CanonicalIterator)
/**
*@param source string to get results for
*/
CanonicalIterator::CanonicalIterator(const UnicodeString &sourceStr, UErrorCode &status) :
pieces(NULL),
pieces_length(0),
pieces_lengths(NULL),
current(NULL),
current_length(0),
nfd(*Normalizer2::getNFDInstance(status)),
nfcImpl(*Normalizer2Factory::getNFCImpl(status))
{
if(U_SUCCESS(status) && nfcImpl.ensureCanonIterData(status)) {
setSource(sourceStr, status);
}
}
CanonicalIterator::~CanonicalIterator() {
cleanPieces();
}
void CanonicalIterator::cleanPieces() {
int32_t i = 0;
if(pieces != NULL) {
for(i = 0; i < pieces_length; i++) {
if(pieces[i] != NULL) {
delete[] pieces[i];
}
}
uprv_free(pieces);
pieces = NULL;
pieces_length = 0;
}
if(pieces_lengths != NULL) {
uprv_free(pieces_lengths);
pieces_lengths = NULL;
}
if(current != NULL) {
uprv_free(current);
current = NULL;
current_length = 0;
}
}
/**
*@return gets the source: NOTE: it is the NFD form of source
*/
UnicodeString CanonicalIterator::getSource() {
return source;
}
/**
* Resets the iterator so that one can start again from the beginning.
*/
void CanonicalIterator::reset() {
done = false;
for (int i = 0; i < current_length; ++i) {
current[i] = 0;
}
}
/**
*@return the next string that is canonically equivalent. The value null is returned when
* the iteration is done.
*/
UnicodeString CanonicalIterator::next() {
int32_t i = 0;
if (done) {
buffer.setToBogus();
return buffer;
}
// delete old contents
buffer.remove();
// construct return value
for (i = 0; i < pieces_length; ++i) {
buffer.append(pieces[i][current[i]]);
}
//String result = buffer.toString(); // not needed
// find next value for next time
for (i = current_length - 1; ; --i) {
if (i < 0) {
done = true;
break;
}
current[i]++;
if (current[i] < pieces_lengths[i]) break; // got sequence
current[i] = 0;
}
return buffer;
}
/**
*@param set the source string to iterate against. This allows the same iterator to be used
* while changing the source string, saving object creation.
*/
void CanonicalIterator::setSource(const UnicodeString &newSource, UErrorCode &status) {
int32_t list_length = 0;
UChar32 cp = 0;
int32_t start = 0;
int32_t i = 0;
UnicodeString *list = NULL;
nfd.normalize(newSource, source, status);
if(U_FAILURE(status)) {
return;
}
done = false;
cleanPieces();
// catch degenerate case
if (newSource.length() == 0) {
pieces = (UnicodeString **)uprv_malloc(sizeof(UnicodeString *));
pieces_lengths = (int32_t*)uprv_malloc(1 * sizeof(int32_t));
pieces_length = 1;
current = (int32_t*)uprv_malloc(1 * sizeof(int32_t));
current_length = 1;
if (pieces == NULL || pieces_lengths == NULL || current == NULL) {
status = U_MEMORY_ALLOCATION_ERROR;
goto CleanPartialInitialization;
}
current[0] = 0;
pieces[0] = new UnicodeString[1];
pieces_lengths[0] = 1;
if (pieces[0] == 0) {
status = U_MEMORY_ALLOCATION_ERROR;
goto CleanPartialInitialization;
}
return;
}
list = new UnicodeString[source.length()];
if (list == 0) {
status = U_MEMORY_ALLOCATION_ERROR;
goto CleanPartialInitialization;
}
// i should initially be the number of code units at the
// start of the string
i = U16_LENGTH(source.char32At(0));
// int32_t i = 1;
// find the segments
// This code iterates through the source string and
// extracts segments that end up on a codepoint that
// doesn't start any decompositions. (Analysis is done
// on the NFD form - see above).
for (; i < source.length(); i += U16_LENGTH(cp)) {
cp = source.char32At(i);
if (nfcImpl.isCanonSegmentStarter(cp)) {
source.extract(start, i-start, list[list_length++]); // add up to i
start = i;
}
}
source.extract(start, i-start, list[list_length++]); // add last one
// allocate the arrays, and find the strings that are CE to each segment
pieces = (UnicodeString **)uprv_malloc(list_length * sizeof(UnicodeString *));
pieces_length = list_length;
pieces_lengths = (int32_t*)uprv_malloc(list_length * sizeof(int32_t));
current = (int32_t*)uprv_malloc(list_length * sizeof(int32_t));
current_length = list_length;
if (pieces == NULL || pieces_lengths == NULL || current == NULL) {
status = U_MEMORY_ALLOCATION_ERROR;
goto CleanPartialInitialization;
}
for (i = 0; i < current_length; i++) {
current[i] = 0;
}
// for each segment, get all the combinations that can produce
// it after NFD normalization
for (i = 0; i < pieces_length; ++i) {
//if (PROGRESS) printf("SEGMENT\n");
pieces[i] = getEquivalents(list[i], pieces_lengths[i], status);
}
delete[] list;
return;
// Common section to cleanup all local variables and reset object variables.
CleanPartialInitialization:
if (list != NULL) {
delete[] list;
}
cleanPieces();
}
/**
* Dumb recursive implementation of permutation.
* TODO: optimize
* @param source the string to find permutations for
* @return the results in a set.
*/
void U_EXPORT2 CanonicalIterator::permute(UnicodeString &source, UBool skipZeros, Hashtable *result, UErrorCode &status) {
if(U_FAILURE(status)) {
return;
}
//if (PROGRESS) printf("Permute: %s\n", UToS(Tr(source)));
int32_t i = 0;
// optimization:
// if zero or one character, just return a set with it
// we check for length < 2 to keep from counting code points all the time
if (source.length() <= 2 && source.countChar32() <= 1) {
UnicodeString *toPut = new UnicodeString(source);
/* test for NULL */
if (toPut == 0) {
status = U_MEMORY_ALLOCATION_ERROR;
return;
}
result->put(source, toPut, status);
return;
}
// otherwise iterate through the string, and recursively permute all the other characters
UChar32 cp;
Hashtable subpermute(status);
if(U_FAILURE(status)) {
return;
}
subpermute.setValueDeleter(uprv_deleteUObject);
for (i = 0; i < source.length(); i += U16_LENGTH(cp)) {
cp = source.char32At(i);
const UHashElement *ne = NULL;
int32_t el = UHASH_FIRST;
UnicodeString subPermuteString = source;
// optimization:
// if the character is canonical combining class zero,
// don't permute it
if (skipZeros && i != 0 && u_getCombiningClass(cp) == 0) {
//System.out.println("Skipping " + Utility.hex(UTF16.valueOf(source, i)));
continue;
}
subpermute.removeAll();
// see what the permutations of the characters before and after this one are
//Hashtable *subpermute = permute(source.substring(0,i) + source.substring(i + UTF16.getCharCount(cp)));
permute(subPermuteString.remove(i, U16_LENGTH(cp)), skipZeros, &subpermute, status);
/* Test for buffer overflows */
if(U_FAILURE(status)) {
return;
}
// The upper remove is destructive. The question is do we have to make a copy, or we don't care about the contents
// of source at this point.
// prefix this character to all of them
ne = subpermute.nextElement(el);
while (ne != NULL) {
UnicodeString *permRes = (UnicodeString *)(ne->value.pointer);
UnicodeString *chStr = new UnicodeString(cp);
//test for NULL
if (chStr == NULL) {
status = U_MEMORY_ALLOCATION_ERROR;
return;
}
chStr->append(*permRes); //*((UnicodeString *)(ne->value.pointer));
//if (PROGRESS) printf(" Piece: %s\n", UToS(*chStr));
result->put(*chStr, chStr, status);
ne = subpermute.nextElement(el);
}
}
//return result;
}
// privates
// we have a segment, in NFD. Find all the strings that are canonically equivalent to it.
UnicodeString* CanonicalIterator::getEquivalents(const UnicodeString &segment, int32_t &result_len, UErrorCode &status) {
Hashtable result(status);
Hashtable permutations(status);
Hashtable basic(status);
if (U_FAILURE(status)) {
return 0;
}
result.setValueDeleter(uprv_deleteUObject);
permutations.setValueDeleter(uprv_deleteUObject);
basic.setValueDeleter(uprv_deleteUObject);
UChar USeg[256];
int32_t segLen = segment.extract(USeg, 256, status);
getEquivalents2(&basic, USeg, segLen, status);
// now get all the permutations
// add only the ones that are canonically equivalent
// TODO: optimize by not permuting any class zero.
const UHashElement *ne = NULL;
int32_t el = UHASH_FIRST;
//Iterator it = basic.iterator();
ne = basic.nextElement(el);
//while (it.hasNext())
while (ne != NULL) {
//String item = (String) it.next();
UnicodeString item = *((UnicodeString *)(ne->value.pointer));
permutations.removeAll();
permute(item, CANITER_SKIP_ZEROES, &permutations, status);
const UHashElement *ne2 = NULL;
int32_t el2 = UHASH_FIRST;
//Iterator it2 = permutations.iterator();
ne2 = permutations.nextElement(el2);
//while (it2.hasNext())
while (ne2 != NULL) {
//String possible = (String) it2.next();
//UnicodeString *possible = new UnicodeString(*((UnicodeString *)(ne2->value.pointer)));
UnicodeString possible(*((UnicodeString *)(ne2->value.pointer)));
UnicodeString attempt;
nfd.normalize(possible, attempt, status);
// TODO: check if operator == is semanticaly the same as attempt.equals(segment)
if (attempt==segment) {
//if (PROGRESS) printf("Adding Permutation: %s\n", UToS(Tr(*possible)));
// TODO: use the hashtable just to catch duplicates - store strings directly (somehow).
result.put(possible, new UnicodeString(possible), status); //add(possible);
} else {
//if (PROGRESS) printf("-Skipping Permutation: %s\n", UToS(Tr(*possible)));
}
ne2 = permutations.nextElement(el2);
}
ne = basic.nextElement(el);
}
/* Test for buffer overflows */
if(U_FAILURE(status)) {
return 0;
}
// convert into a String[] to clean up storage
//String[] finalResult = new String[result.size()];
UnicodeString *finalResult = NULL;
int32_t resultCount;
if((resultCount = result.count()) != 0) {
finalResult = new UnicodeString[resultCount];
if (finalResult == 0) {
status = U_MEMORY_ALLOCATION_ERROR;
return NULL;
}
}
else {
status = U_ILLEGAL_ARGUMENT_ERROR;
return NULL;
}
//result.toArray(finalResult);
result_len = 0;
el = UHASH_FIRST;
ne = result.nextElement(el);
while(ne != NULL) {
finalResult[result_len++] = *((UnicodeString *)(ne->value.pointer));
ne = result.nextElement(el);
}
return finalResult;
}
Hashtable *CanonicalIterator::getEquivalents2(Hashtable *fillinResult, const UChar *segment, int32_t segLen, UErrorCode &status) {
if (U_FAILURE(status)) {
return NULL;
}
//if (PROGRESS) printf("Adding: %s\n", UToS(Tr(segment)));
UnicodeString toPut(segment, segLen);
fillinResult->put(toPut, new UnicodeString(toPut), status);
UnicodeSet starts;
// cycle through all the characters
UChar32 cp;
for (int32_t i = 0; i < segLen; i += U16_LENGTH(cp)) {
// see if any character is at the start of some decomposition
U16_GET(segment, 0, i, segLen, cp);
if (!nfcImpl.getCanonStartSet(cp, starts)) {
continue;
}
// if so, see which decompositions match
UnicodeSetIterator iter(starts);
while (iter.next()) {
UChar32 cp2 = iter.getCodepoint();
Hashtable remainder(status);
remainder.setValueDeleter(uprv_deleteUObject);
if (extract(&remainder, cp2, segment, segLen, i, status) == NULL) {
continue;
}
// there were some matches, so add all the possibilities to the set.
UnicodeString prefix(segment, i);
prefix += cp2;
int32_t el = UHASH_FIRST;
const UHashElement *ne = remainder.nextElement(el);
while (ne != NULL) {
UnicodeString item = *((UnicodeString *)(ne->value.pointer));
UnicodeString *toAdd = new UnicodeString(prefix);
/* test for NULL */
if (toAdd == 0) {
status = U_MEMORY_ALLOCATION_ERROR;
return NULL;
}
*toAdd += item;
fillinResult->put(*toAdd, toAdd, status);
//if (PROGRESS) printf("Adding: %s\n", UToS(Tr(*toAdd)));
ne = remainder.nextElement(el);
}
}
}
/* Test for buffer overflows */
if(U_FAILURE(status)) {
return NULL;
}
return fillinResult;
}
/**
* See if the decomposition of cp2 is at segment starting at segmentPos
* (with canonical rearrangement!)
* If so, take the remainder, and return the equivalents
*/
Hashtable *CanonicalIterator::extract(Hashtable *fillinResult, UChar32 comp, const UChar *segment, int32_t segLen, int32_t segmentPos, UErrorCode &status) {
//Hashtable *CanonicalIterator::extract(UChar32 comp, const UnicodeString &segment, int32_t segLen, int32_t segmentPos, UErrorCode &status) {
//if (PROGRESS) printf(" extract: %s, ", UToS(Tr(UnicodeString(comp))));
//if (PROGRESS) printf("%s, %i\n", UToS(Tr(segment)), segmentPos);
if (U_FAILURE(status)) {
return NULL;
}
UnicodeString temp(comp);
int32_t inputLen=temp.length();
UnicodeString decompString;
nfd.normalize(temp, decompString, status);
if (U_FAILURE(status)) {
return NULL;
}
if (decompString.isBogus()) {
status = U_MEMORY_ALLOCATION_ERROR;
return NULL;
}
const UChar *decomp=decompString.getBuffer();
int32_t decompLen=decompString.length();
// See if it matches the start of segment (at segmentPos)
UBool ok = false;
UChar32 cp;
int32_t decompPos = 0;
UChar32 decompCp;
U16_NEXT(decomp, decompPos, decompLen, decompCp);
int32_t i = segmentPos;
while(i < segLen) {
U16_NEXT(segment, i, segLen, cp);
if (cp == decompCp) { // if equal, eat another cp from decomp
//if (PROGRESS) printf(" matches: %s\n", UToS(Tr(UnicodeString(cp))));
if (decompPos == decompLen) { // done, have all decomp characters!
temp.append(segment+i, segLen-i);
ok = true;
break;
}
U16_NEXT(decomp, decompPos, decompLen, decompCp);
} else {
//if (PROGRESS) printf(" buffer: %s\n", UToS(Tr(UnicodeString(cp))));
// brute force approach
temp.append(cp);
/* TODO: optimize
// since we know that the classes are monotonically increasing, after zero
// e.g. 0 5 7 9 0 3
// we can do an optimization
// there are only a few cases that work: zero, less, same, greater
// if both classes are the same, we fail
// if the decomp class < the segment class, we fail
segClass = getClass(cp);
if (decompClass <= segClass) return null;
*/
}
}
if (!ok)
return NULL; // we failed, characters left over
//if (PROGRESS) printf("Matches\n");
if (inputLen == temp.length()) {
fillinResult->put(UnicodeString(), new UnicodeString(), status);
return fillinResult; // succeed, but no remainder
}
// brute force approach
// check to make sure result is canonically equivalent
UnicodeString trial;
nfd.normalize(temp, trial, status);
if(U_FAILURE(status) || trial.compare(segment+segmentPos, segLen - segmentPos) != 0) {
return NULL;
}
return getEquivalents2(fillinResult, temp.getBuffer()+inputLen, temp.length()-inputLen, status);
}
U_NAMESPACE_END
#endif /* #if !UCONFIG_NO_NORMALIZATION */
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