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      1 /*
      2 **********************************************************************
      3 *   Copyright (C) 1999-2011, International Business Machines
      4 *   Corporation and others.  All Rights Reserved.
      5 **********************************************************************
      6 *   Date        Name        Description
      7 *   11/17/99    aliu        Creation.
      8 **********************************************************************
      9 */
     10 
     11 #include "unicode/utypes.h"
     12 
     13 #if !UCONFIG_NO_TRANSLITERATION
     14 
     15 #include "unicode/unifilt.h"
     16 #include "unicode/uniset.h"
     17 #include "cpdtrans.h"
     18 #include "uvector.h"
     19 #include "tridpars.h"
     20 #include "cmemory.h"
     21 
     22 // keep in sync with Transliterator
     23 //static const UChar ID_SEP   = 0x002D; /*-*/
     24 static const UChar ID_DELIM = 0x003B; /*;*/
     25 static const UChar NEWLINE  = 10;
     26 
     27 static const UChar COLON_COLON[] = {0x3A, 0x3A, 0}; //"::"
     28 
     29 U_NAMESPACE_BEGIN
     30 
     31 const UChar CompoundTransliterator::PASS_STRING[] = { 0x0025, 0x0050, 0x0061, 0x0073, 0x0073, 0 }; // "%Pass"
     32 
     33 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(CompoundTransliterator)
     34 
     35 /**
     36  * Constructs a new compound transliterator given an array of
     37  * transliterators.  The array of transliterators may be of any
     38  * length, including zero or one, however, useful compound
     39  * transliterators have at least two components.
     40  * @param transliterators array of <code>Transliterator</code>
     41  * objects
     42  * @param transliteratorCount The number of
     43  * <code>Transliterator</code> objects in transliterators.
     44  * @param filter the filter.  Any character for which
     45  * <tt>filter.contains()</tt> returns <tt>false</tt> will not be
     46  * altered by this transliterator.  If <tt>filter</tt> is
     47  * <tt>null</tt> then no filtering is applied.
     48  */
     49 CompoundTransliterator::CompoundTransliterator(
     50                            Transliterator* const transliterators[],
     51                            int32_t transliteratorCount,
     52                            UnicodeFilter* adoptedFilter) :
     53     Transliterator(joinIDs(transliterators, transliteratorCount), adoptedFilter),
     54     trans(0), count(0), numAnonymousRBTs(0)  {
     55     setTransliterators(transliterators, transliteratorCount);
     56 }
     57 
     58 /**
     59  * Splits an ID of the form "ID;ID;..." into a compound using each
     60  * of the IDs.
     61  * @param id of above form
     62  * @param forward if false, does the list in reverse order, and
     63  * takes the inverse of each ID.
     64  */
     65 CompoundTransliterator::CompoundTransliterator(const UnicodeString& id,
     66                               UTransDirection direction,
     67                               UnicodeFilter* adoptedFilter,
     68                               UParseError& /*parseError*/,
     69                               UErrorCode& status) :
     70     Transliterator(id, adoptedFilter),
     71     trans(0), numAnonymousRBTs(0) {
     72     // TODO add code for parseError...currently unused, but
     73     // later may be used by parsing code...
     74     init(id, direction, TRUE, status);
     75 }
     76 
     77 CompoundTransliterator::CompoundTransliterator(const UnicodeString& id,
     78                               UParseError& /*parseError*/,
     79                               UErrorCode& status) :
     80     Transliterator(id, 0), // set filter to 0 here!
     81     trans(0), numAnonymousRBTs(0) {
     82     // TODO add code for parseError...currently unused, but
     83     // later may be used by parsing code...
     84     init(id, UTRANS_FORWARD, TRUE, status);
     85 }
     86 
     87 
     88 /**
     89  * Private constructor for use of TransliteratorAlias
     90  */
     91 CompoundTransliterator::CompoundTransliterator(const UnicodeString& newID,
     92                                               UVector& list,
     93                                               UnicodeFilter* adoptedFilter,
     94                                               int32_t anonymousRBTs,
     95                                               UParseError& /*parseError*/,
     96                                               UErrorCode& status) :
     97     Transliterator(newID, adoptedFilter),
     98     trans(0), numAnonymousRBTs(anonymousRBTs)
     99 {
    100     init(list, UTRANS_FORWARD, FALSE, status);
    101 }
    102 
    103 /**
    104  * Private constructor for Transliterator from a vector of
    105  * transliterators.  The caller is responsible for fixing up the
    106  * ID.
    107  */
    108 CompoundTransliterator::CompoundTransliterator(UVector& list,
    109                                                UParseError& /*parseError*/,
    110                                                UErrorCode& status) :
    111     Transliterator(UnicodeString(), NULL),
    112     trans(0), numAnonymousRBTs(0)
    113 {
    114     // TODO add code for parseError...currently unused, but
    115     // later may be used by parsing code...
    116     init(list, UTRANS_FORWARD, FALSE, status);
    117     // assume caller will fixup ID
    118 }
    119 
    120 CompoundTransliterator::CompoundTransliterator(UVector& list,
    121                                                int32_t anonymousRBTs,
    122                                                UParseError& /*parseError*/,
    123                                                UErrorCode& status) :
    124     Transliterator(UnicodeString(), NULL),
    125     trans(0), numAnonymousRBTs(anonymousRBTs)
    126 {
    127     init(list, UTRANS_FORWARD, FALSE, status);
    128 }
    129 
    130 /**
    131  * Finish constructing a transliterator: only to be called by
    132  * constructors.  Before calling init(), set trans and filter to NULL.
    133  * @param id the id containing ';'-separated entries
    134  * @param direction either FORWARD or REVERSE
    135  * @param idSplitPoint the index into id at which the
    136  * adoptedSplitTransliterator should be inserted, if there is one, or
    137  * -1 if there is none.
    138  * @param adoptedSplitTransliterator a transliterator to be inserted
    139  * before the entry at offset idSplitPoint in the id string.  May be
    140  * NULL to insert no entry.
    141  * @param fixReverseID if TRUE, then reconstruct the ID of reverse
    142  * entries by calling getID() of component entries.  Some constructors
    143  * do not require this because they apply a facade ID anyway.
    144  * @param status the error code indicating success or failure
    145  */
    146 void CompoundTransliterator::init(const UnicodeString& id,
    147                                   UTransDirection direction,
    148                                   UBool fixReverseID,
    149                                   UErrorCode& status) {
    150     // assert(trans == 0);
    151 
    152     if (U_FAILURE(status)) {
    153         return;
    154     }
    155 
    156     UVector list(status);
    157     UnicodeSet* compoundFilter = NULL;
    158     UnicodeString regenID;
    159     if (!TransliteratorIDParser::parseCompoundID(id, direction,
    160                                       regenID, list, compoundFilter)) {
    161         status = U_INVALID_ID;
    162         delete compoundFilter;
    163         return;
    164     }
    165 
    166     TransliteratorIDParser::instantiateList(list, status);
    167 
    168     init(list, direction, fixReverseID, status);
    169 
    170     if (compoundFilter != NULL) {
    171         adoptFilter(compoundFilter);
    172     }
    173 }
    174 
    175 /**
    176  * Finish constructing a transliterator: only to be called by
    177  * constructors.  Before calling init(), set trans and filter to NULL.
    178  * @param list a vector of transliterator objects to be adopted.  It
    179  * should NOT be empty.  The list should be in declared order.  That
    180  * is, it should be in the FORWARD order; if direction is REVERSE then
    181  * the list order will be reversed.
    182  * @param direction either FORWARD or REVERSE
    183  * @param fixReverseID if TRUE, then reconstruct the ID of reverse
    184  * entries by calling getID() of component entries.  Some constructors
    185  * do not require this because they apply a facade ID anyway.
    186  * @param status the error code indicating success or failure
    187  */
    188 void CompoundTransliterator::init(UVector& list,
    189                                   UTransDirection direction,
    190                                   UBool fixReverseID,
    191                                   UErrorCode& status) {
    192     // assert(trans == 0);
    193 
    194     // Allocate array
    195     if (U_SUCCESS(status)) {
    196         count = list.size();
    197         trans = (Transliterator **)uprv_malloc(count * sizeof(Transliterator *));
    198         /* test for NULL */
    199         if (trans == 0) {
    200             status = U_MEMORY_ALLOCATION_ERROR;
    201             return;
    202         }
    203     }
    204 
    205     if (U_FAILURE(status) || trans == 0) {
    206          // assert(trans == 0);
    207         return;
    208     }
    209 
    210     // Move the transliterators from the vector into an array.
    211     // Reverse the order if necessary.
    212     int32_t i;
    213     for (i=0; i<count; ++i) {
    214         int32_t j = (direction == UTRANS_FORWARD) ? i : count - 1 - i;
    215         trans[i] = (Transliterator*) list.elementAt(j);
    216     }
    217 
    218     // If the direction is UTRANS_REVERSE then we may need to fix the
    219     // ID.
    220     if (direction == UTRANS_REVERSE && fixReverseID) {
    221         UnicodeString newID;
    222         for (i=0; i<count; ++i) {
    223             if (i > 0) {
    224                 newID.append(ID_DELIM);
    225             }
    226             newID.append(trans[i]->getID());
    227         }
    228         setID(newID);
    229     }
    230 
    231     computeMaximumContextLength();
    232 }
    233 
    234 /**
    235  * Return the IDs of the given list of transliterators, concatenated
    236  * with ID_DELIM delimiting them.  Equivalent to the perlish expression
    237  * join(ID_DELIM, map($_.getID(), transliterators).
    238  */
    239 UnicodeString CompoundTransliterator::joinIDs(Transliterator* const transliterators[],
    240                                               int32_t transCount) {
    241     UnicodeString id;
    242     for (int32_t i=0; i<transCount; ++i) {
    243         if (i > 0) {
    244             id.append(ID_DELIM);
    245         }
    246         id.append(transliterators[i]->getID());
    247     }
    248     return id; // Return temporary
    249 }
    250 
    251 /**
    252  * Copy constructor.
    253  */
    254 CompoundTransliterator::CompoundTransliterator(const CompoundTransliterator& t) :
    255     Transliterator(t), trans(0), count(0), numAnonymousRBTs(-1) {
    256     *this = t;
    257 }
    258 
    259 /**
    260  * Destructor
    261  */
    262 CompoundTransliterator::~CompoundTransliterator() {
    263     freeTransliterators();
    264 }
    265 
    266 void CompoundTransliterator::freeTransliterators(void) {
    267     if (trans != 0) {
    268         for (int32_t i=0; i<count; ++i) {
    269             delete trans[i];
    270         }
    271         uprv_free(trans);
    272     }
    273     trans = 0;
    274     count = 0;
    275 }
    276 
    277 /**
    278  * Assignment operator.
    279  */
    280 CompoundTransliterator& CompoundTransliterator::operator=(
    281                                              const CompoundTransliterator& t)
    282 {
    283     Transliterator::operator=(t);
    284     int32_t i = 0;
    285     UBool failed = FALSE;
    286     if (trans != NULL) {
    287         for (i=0; i<count; ++i) {
    288             delete trans[i];
    289             trans[i] = 0;
    290         }
    291     }
    292     if (t.count > count) {
    293         if (trans != NULL) {
    294             uprv_free(trans);
    295         }
    296         trans = (Transliterator **)uprv_malloc(t.count * sizeof(Transliterator *));
    297     }
    298     count = t.count;
    299     if (trans != NULL) {
    300         for (i=0; i<count; ++i) {
    301             trans[i] = t.trans[i]->clone();
    302             if (trans[i] == NULL) {
    303                 failed = TRUE;
    304                 break;
    305             }
    306         }
    307     }
    308 
    309     // if memory allocation failed delete backwards trans array
    310     if (failed && i > 0) {
    311         int32_t n;
    312         for (n = i-1; n >= 0; n--) {
    313             uprv_free(trans[n]);
    314             trans[n] = NULL;
    315         }
    316     }
    317     numAnonymousRBTs = t.numAnonymousRBTs;
    318     return *this;
    319 }
    320 
    321 /**
    322  * Transliterator API.
    323  */
    324 Transliterator* CompoundTransliterator::clone(void) const {
    325     return new CompoundTransliterator(*this);
    326 }
    327 
    328 /**
    329  * Returns the number of transliterators in this chain.
    330  * @return number of transliterators in this chain.
    331  */
    332 int32_t CompoundTransliterator::getCount(void) const {
    333     return count;
    334 }
    335 
    336 /**
    337  * Returns the transliterator at the given index in this chain.
    338  * @param index index into chain, from 0 to <code>getCount() - 1</code>
    339  * @return transliterator at the given index
    340  */
    341 const Transliterator& CompoundTransliterator::getTransliterator(int32_t index) const {
    342     return *trans[index];
    343 }
    344 
    345 void CompoundTransliterator::setTransliterators(Transliterator* const transliterators[],
    346                                                 int32_t transCount) {
    347     Transliterator** a = (Transliterator **)uprv_malloc(transCount * sizeof(Transliterator *));
    348     if (a == NULL) {
    349         return;
    350     }
    351     int32_t i = 0;
    352     UBool failed = FALSE;
    353     for (i=0; i<transCount; ++i) {
    354         a[i] = transliterators[i]->clone();
    355         if (a[i] == NULL) {
    356             failed = TRUE;
    357             break;
    358         }
    359     }
    360     if (failed && i > 0) {
    361         int32_t n;
    362         for (n = i-1; n >= 0; n--) {
    363             uprv_free(a[n]);
    364             a[n] = NULL;
    365         }
    366         return;
    367     }
    368     adoptTransliterators(a, transCount);
    369 }
    370 
    371 void CompoundTransliterator::adoptTransliterators(Transliterator* adoptedTransliterators[],
    372                                                   int32_t transCount) {
    373     // First free trans[] and set count to zero.  Once this is done,
    374     // orphan the filter.  Set up the new trans[].
    375     freeTransliterators();
    376     trans = adoptedTransliterators;
    377     count = transCount;
    378     computeMaximumContextLength();
    379     setID(joinIDs(trans, count));
    380 }
    381 
    382 /**
    383  * Append c to buf, unless buf is empty or buf already ends in c.
    384  */
    385 static void _smartAppend(UnicodeString& buf, UChar c) {
    386     if (buf.length() != 0 &&
    387         buf.charAt(buf.length() - 1) != c) {
    388         buf.append(c);
    389     }
    390 }
    391 
    392 UnicodeString& CompoundTransliterator::toRules(UnicodeString& rulesSource,
    393                                                UBool escapeUnprintable) const {
    394     // We do NOT call toRules() on our component transliterators, in
    395     // general.  If we have several rule-based transliterators, this
    396     // yields a concatenation of the rules -- not what we want.  We do
    397     // handle compound RBT transliterators specially -- those for which
    398     // compoundRBTIndex >= 0.  For the transliterator at compoundRBTIndex,
    399     // we do call toRules() recursively.
    400     rulesSource.truncate(0);
    401     if (numAnonymousRBTs >= 1 && getFilter() != NULL) {
    402         // If we are a compound RBT and if we have a global
    403         // filter, then emit it at the top.
    404         UnicodeString pat;
    405         rulesSource.append(COLON_COLON, 2).append(getFilter()->toPattern(pat, escapeUnprintable)).append(ID_DELIM);
    406     }
    407     for (int32_t i=0; i<count; ++i) {
    408         UnicodeString rule;
    409 
    410         // Anonymous RuleBasedTransliterators (inline rules and
    411         // ::BEGIN/::END blocks) are given IDs that begin with
    412         // "%Pass": use toRules() to write all the rules to the output
    413         // (and insert "::Null;" if we have two in a row)
    414         if (trans[i]->getID().startsWith(PASS_STRING, 5)) {
    415             trans[i]->toRules(rule, escapeUnprintable);
    416             if (numAnonymousRBTs > 1 && i > 0 && trans[i - 1]->getID().startsWith(PASS_STRING, 5))
    417                 rule = UNICODE_STRING_SIMPLE("::Null;") + rule;
    418 
    419         // we also use toRules() on CompoundTransliterators (which we
    420         // check for by looking for a semicolon in the ID)-- this gets
    421         // the list of their child transliterators output in the right
    422         // format
    423         } else if (trans[i]->getID().indexOf(ID_DELIM) >= 0) {
    424             trans[i]->toRules(rule, escapeUnprintable);
    425 
    426         // for everything else, use Transliterator::toRules()
    427         } else {
    428             trans[i]->Transliterator::toRules(rule, escapeUnprintable);
    429         }
    430         _smartAppend(rulesSource, NEWLINE);
    431         rulesSource.append(rule);
    432         _smartAppend(rulesSource, ID_DELIM);
    433     }
    434     return rulesSource;
    435 }
    436 
    437 /**
    438  * Implement Transliterator framework
    439  */
    440 void CompoundTransliterator::handleGetSourceSet(UnicodeSet& result) const {
    441     UnicodeSet set;
    442     result.clear();
    443     for (int32_t i=0; i<count; ++i) {
    444     result.addAll(trans[i]->getSourceSet(set));
    445     // Take the example of Hiragana-Latin.  This is really
    446     // Hiragana-Katakana; Katakana-Latin.  The source set of
    447     // these two is roughly [:Hiragana:] and [:Katakana:].
    448     // But the source set for the entire transliterator is
    449     // actually [:Hiragana:] ONLY -- that is, the first
    450     // non-empty source set.
    451 
    452     // This is a heuristic, and not 100% reliable.
    453     if (!result.isEmpty()) {
    454         break;
    455     }
    456     }
    457 }
    458 
    459 /**
    460  * Override Transliterator framework
    461  */
    462 UnicodeSet& CompoundTransliterator::getTargetSet(UnicodeSet& result) const {
    463     UnicodeSet set;
    464     result.clear();
    465     for (int32_t i=0; i<count; ++i) {
    466     // This is a heuristic, and not 100% reliable.
    467     result.addAll(trans[i]->getTargetSet(set));
    468     }
    469     return result;
    470 }
    471 
    472 /**
    473  * Implements {@link Transliterator#handleTransliterate}.
    474  */
    475 void CompoundTransliterator::handleTransliterate(Replaceable& text, UTransPosition& index,
    476                                                  UBool incremental) const {
    477     /* Call each transliterator with the same contextStart and
    478      * start, but with the limit as modified
    479      * by preceding transliterators.  The start index must be
    480      * reset for each transliterator to give each a chance to
    481      * transliterate the text.  The initial contextStart index is known
    482      * to still point to the same place after each transliterator
    483      * is called because each transliterator will not change the
    484      * text between contextStart and the initial start index.
    485      *
    486      * IMPORTANT: After the first transliterator, each subsequent
    487      * transliterator only gets to transliterate text committed by
    488      * preceding transliterators; that is, the start (output
    489      * value) of transliterator i becomes the limit (input value)
    490      * of transliterator i+1.  Finally, the overall limit is fixed
    491      * up before we return.
    492      *
    493      * Assumptions we make here:
    494      * (1) contextStart <= start <= limit <= contextLimit <= text.length()
    495      * (2) start <= start' <= limit'  ;cursor doesn't move back
    496      * (3) start <= limit'            ;text before cursor unchanged
    497      * - start' is the value of start after calling handleKT
    498      * - limit' is the value of limit after calling handleKT
    499      */
    500 
    501     /**
    502      * Example: 3 transliterators.  This example illustrates the
    503      * mechanics we need to implement.  C, S, and L are the contextStart,
    504      * start, and limit.  gl is the globalLimit.  contextLimit is
    505      * equal to limit throughout.
    506      *
    507      * 1. h-u, changes hex to Unicode
    508      *
    509      *    4  7  a  d  0      4  7  a
    510      *    abc/u0061/u    =>  abca/u
    511      *    C  S       L       C   S L   gl=f->a
    512      *
    513      * 2. upup, changes "x" to "XX"
    514      *
    515      *    4  7  a       4  7  a
    516      *    abca/u    =>  abcAA/u
    517      *    C  SL         C    S
    518      *                       L    gl=a->b
    519      * 3. u-h, changes Unicode to hex
    520      *
    521      *    4  7  a        4  7  a  d  0  3
    522      *    abcAA/u    =>  abc/u0041/u0041/u
    523      *    C  S L         C              S
    524      *                                  L   gl=b->15
    525      * 4. return
    526      *
    527      *    4  7  a  d  0  3
    528      *    abc/u0041/u0041/u
    529      *    C S L
    530      */
    531 
    532     if (count < 1) {
    533         index.start = index.limit;
    534         return; // Short circuit for empty compound transliterators
    535     }
    536 
    537     // compoundLimit is the limit value for the entire compound
    538     // operation.  We overwrite index.limit with the previous
    539     // index.start.  After each transliteration, we update
    540     // compoundLimit for insertions or deletions that have happened.
    541     int32_t compoundLimit = index.limit;
    542 
    543     // compoundStart is the start for the entire compound
    544     // operation.
    545     int32_t compoundStart = index.start;
    546 
    547     int32_t delta = 0; // delta in length
    548 
    549     // Give each transliterator a crack at the run of characters.
    550     // See comments at the top of the method for more detail.
    551     for (int32_t i=0; i<count; ++i) {
    552         index.start = compoundStart; // Reset start
    553         int32_t limit = index.limit;
    554 
    555         if (index.start == index.limit) {
    556             // Short circuit for empty range
    557             break;
    558         }
    559 
    560         trans[i]->filteredTransliterate(text, index, incremental);
    561 
    562         // In a properly written transliterator, start == limit after
    563         // handleTransliterate() returns when incremental is false.
    564         // Catch cases where the subclass doesn't do this, and throw
    565         // an exception.  (Just pinning start to limit is a bad idea,
    566         // because what's probably happening is that the subclass
    567         // isn't transliterating all the way to the end, and it should
    568         // in non-incremental mode.)
    569         if (!incremental && index.start != index.limit) {
    570             // We can't throw an exception, so just fudge things
    571             index.start = index.limit;
    572         }
    573 
    574         // Cumulative delta for insertions/deletions
    575         delta += index.limit - limit;
    576 
    577         if (incremental) {
    578             // In the incremental case, only allow subsequent
    579             // transliterators to modify what has already been
    580             // completely processed by prior transliterators.  In the
    581             // non-incrmental case, allow each transliterator to
    582             // process the entire text.
    583             index.limit = index.start;
    584         }
    585     }
    586 
    587     compoundLimit += delta;
    588 
    589     // Start is good where it is -- where the last transliterator left
    590     // it.  Limit needs to be put back where it was, modulo
    591     // adjustments for deletions/insertions.
    592     index.limit = compoundLimit;
    593 }
    594 
    595 /**
    596  * Sets the length of the longest context required by this transliterator.
    597  * This is <em>preceding</em> context.
    598  */
    599 void CompoundTransliterator::computeMaximumContextLength(void) {
    600     int32_t max = 0;
    601     for (int32_t i=0; i<count; ++i) {
    602         int32_t len = trans[i]->getMaximumContextLength();
    603         if (len > max) {
    604             max = len;
    605         }
    606     }
    607     setMaximumContextLength(max);
    608 }
    609 
    610 U_NAMESPACE_END
    611 
    612 #endif /* #if !UCONFIG_NO_TRANSLITERATION */
    613 
    614 /* eof */
    615