intl/icu/source/i18n/rbt_pars.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author
Michael Schloh von Bennewitz <michael@schloh.com>
date
Thu, 22 Jan 2015 13:21:57 +0100
branch
TOR_BUG_9701
changeset 15
b8a032363ba2
permissions
-rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     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  */
    11 #include "unicode/utypes.h"
    13 #if !UCONFIG_NO_TRANSLITERATION
    15 #include "unicode/uobject.h"
    16 #include "unicode/parseerr.h"
    17 #include "unicode/parsepos.h"
    18 #include "unicode/putil.h"
    19 #include "unicode/uchar.h"
    20 #include "unicode/ustring.h"
    21 #include "unicode/uniset.h"
    22 #include "unicode/utf16.h"
    23 #include "cstring.h"
    24 #include "funcrepl.h"
    25 #include "hash.h"
    26 #include "quant.h"
    27 #include "rbt.h"
    28 #include "rbt_data.h"
    29 #include "rbt_pars.h"
    30 #include "rbt_rule.h"
    31 #include "strmatch.h"
    32 #include "strrepl.h"
    33 #include "unicode/symtable.h"
    34 #include "tridpars.h"
    35 #include "uvector.h"
    36 #include "hash.h"
    37 #include "patternprops.h"
    38 #include "util.h"
    39 #include "cmemory.h"
    40 #include "uprops.h"
    41 #include "putilimp.h"
    43 // Operators
    44 #define VARIABLE_DEF_OP ((UChar)0x003D) /*=*/
    45 #define FORWARD_RULE_OP ((UChar)0x003E) /*>*/
    46 #define REVERSE_RULE_OP ((UChar)0x003C) /*<*/
    47 #define FWDREV_RULE_OP  ((UChar)0x007E) /*~*/ // internal rep of <> op
    49 // Other special characters
    50 #define QUOTE             ((UChar)0x0027) /*'*/
    51 #define ESCAPE            ((UChar)0x005C) /*\*/
    52 #define END_OF_RULE       ((UChar)0x003B) /*;*/
    53 #define RULE_COMMENT_CHAR ((UChar)0x0023) /*#*/
    55 #define SEGMENT_OPEN       ((UChar)0x0028) /*(*/
    56 #define SEGMENT_CLOSE      ((UChar)0x0029) /*)*/
    57 #define CONTEXT_ANTE       ((UChar)0x007B) /*{*/
    58 #define CONTEXT_POST       ((UChar)0x007D) /*}*/
    59 #define CURSOR_POS         ((UChar)0x007C) /*|*/
    60 #define CURSOR_OFFSET      ((UChar)0x0040) /*@*/
    61 #define ANCHOR_START       ((UChar)0x005E) /*^*/
    62 #define KLEENE_STAR        ((UChar)0x002A) /***/
    63 #define ONE_OR_MORE        ((UChar)0x002B) /*+*/
    64 #define ZERO_OR_ONE        ((UChar)0x003F) /*?*/
    66 #define DOT                ((UChar)46)     /*.*/
    68 static const UChar DOT_SET[] = { // "[^[:Zp:][:Zl:]\r\n$]";
    69     91, 94, 91, 58, 90, 112, 58, 93, 91, 58, 90,
    70     108, 58, 93, 92, 114, 92, 110, 36, 93, 0
    71 };
    73 // A function is denoted &Source-Target/Variant(text)
    74 #define FUNCTION           ((UChar)38)     /*&*/
    76 // Aliases for some of the syntax characters. These are provided so
    77 // transliteration rules can be expressed in XML without clashing with
    78 // XML syntax characters '<', '>', and '&'.
    79 #define ALT_REVERSE_RULE_OP ((UChar)0x2190) // Left Arrow
    80 #define ALT_FORWARD_RULE_OP ((UChar)0x2192) // Right Arrow
    81 #define ALT_FWDREV_RULE_OP  ((UChar)0x2194) // Left Right Arrow
    82 #define ALT_FUNCTION        ((UChar)0x2206) // Increment (~Greek Capital Delta)
    84 // Special characters disallowed at the top level
    85 static const UChar ILLEGAL_TOP[] = {41,0}; // ")"
    87 // Special characters disallowed within a segment
    88 static const UChar ILLEGAL_SEG[] = {123,125,124,64,0}; // "{}|@"
    90 // Special characters disallowed within a function argument
    91 static const UChar ILLEGAL_FUNC[] = {94,40,46,42,43,63,123,125,124,64,0}; // "^(.*+?{}|@"
    93 // By definition, the ANCHOR_END special character is a
    94 // trailing SymbolTable.SYMBOL_REF character.
    95 // private static final char ANCHOR_END       = '$';
    97 static const UChar gOPERATORS[] = { // "=><"
    98     VARIABLE_DEF_OP, FORWARD_RULE_OP, REVERSE_RULE_OP,
    99     ALT_FORWARD_RULE_OP, ALT_REVERSE_RULE_OP, ALT_FWDREV_RULE_OP,
   100     0
   101 };
   103 static const UChar HALF_ENDERS[] = { // "=><;"
   104     VARIABLE_DEF_OP, FORWARD_RULE_OP, REVERSE_RULE_OP,
   105     ALT_FORWARD_RULE_OP, ALT_REVERSE_RULE_OP, ALT_FWDREV_RULE_OP,
   106     END_OF_RULE,
   107     0
   108 };
   110 // These are also used in Transliterator::toRules()
   111 static const int32_t ID_TOKEN_LEN = 2;
   112 static const UChar   ID_TOKEN[]   = { 0x3A, 0x3A }; // ':', ':'
   114 /*
   115 commented out until we do real ::BEGIN/::END functionality
   116 static const int32_t BEGIN_TOKEN_LEN = 5;
   117 static const UChar BEGIN_TOKEN[] = { 0x42, 0x45, 0x47, 0x49, 0x4e }; // 'BEGIN'
   119 static const int32_t END_TOKEN_LEN = 3;
   120 static const UChar END_TOKEN[] = { 0x45, 0x4e, 0x44 }; // 'END'
   121 */
   123 U_NAMESPACE_BEGIN
   125 //----------------------------------------------------------------------
   126 // BEGIN ParseData
   127 //----------------------------------------------------------------------
   129 /**
   130  * This class implements the SymbolTable interface.  It is used
   131  * during parsing to give UnicodeSet access to variables that
   132  * have been defined so far.  Note that it uses variablesVector,
   133  * _not_ data.setVariables.
   134  */
   135 class ParseData : public UMemory, public SymbolTable {
   136 public:
   137     const TransliterationRuleData* data; // alias
   139     const UVector* variablesVector; // alias
   141     const Hashtable* variableNames; // alias
   143     ParseData(const TransliterationRuleData* data = 0,
   144               const UVector* variablesVector = 0,
   145               const Hashtable* variableNames = 0);
   147     virtual ~ParseData();
   149     virtual const UnicodeString* lookup(const UnicodeString& s) const;
   151     virtual const UnicodeFunctor* lookupMatcher(UChar32 ch) const;
   153     virtual UnicodeString parseReference(const UnicodeString& text,
   154                                          ParsePosition& pos, int32_t limit) const;
   155     /**
   156      * Return true if the given character is a matcher standin or a plain
   157      * character (non standin).
   158      */
   159     UBool isMatcher(UChar32 ch);
   161     /**
   162      * Return true if the given character is a replacer standin or a plain
   163      * character (non standin).
   164      */
   165     UBool isReplacer(UChar32 ch);
   167 private:
   168     ParseData(const ParseData &other); // forbid copying of this class
   169     ParseData &operator=(const ParseData &other); // forbid copying of this class
   170 };
   172 ParseData::ParseData(const TransliterationRuleData* d,
   173                      const UVector* sets,
   174                      const Hashtable* vNames) :
   175     data(d), variablesVector(sets), variableNames(vNames) {}
   177 ParseData::~ParseData() {}
   179 /**
   180  * Implement SymbolTable API.
   181  */
   182 const UnicodeString* ParseData::lookup(const UnicodeString& name) const {
   183     return (const UnicodeString*) variableNames->get(name);
   184 }
   186 /**
   187  * Implement SymbolTable API.
   188  */
   189 const UnicodeFunctor* ParseData::lookupMatcher(UChar32 ch) const {
   190     // Note that we cannot use data.lookupSet() because the
   191     // set array has not been constructed yet.
   192     const UnicodeFunctor* set = NULL;
   193     int32_t i = ch - data->variablesBase;
   194     if (i >= 0 && i < variablesVector->size()) {
   195         int32_t i = ch - data->variablesBase;
   196         set = (i < variablesVector->size()) ?
   197             (UnicodeFunctor*) variablesVector->elementAt(i) : 0;
   198     }
   199     return set;
   200 }
   202 /**
   203  * Implement SymbolTable API.  Parse out a symbol reference
   204  * name.
   205  */
   206 UnicodeString ParseData::parseReference(const UnicodeString& text,
   207                                         ParsePosition& pos, int32_t limit) const {
   208     int32_t start = pos.getIndex();
   209     int32_t i = start;
   210     UnicodeString result;
   211     while (i < limit) {
   212         UChar c = text.charAt(i);
   213         if ((i==start && !u_isIDStart(c)) || !u_isIDPart(c)) {
   214             break;
   215         }
   216         ++i;
   217     }
   218     if (i == start) { // No valid name chars
   219         return result; // Indicate failure with empty string
   220     }
   221     pos.setIndex(i);
   222     text.extractBetween(start, i, result);
   223     return result;
   224 }
   226 UBool ParseData::isMatcher(UChar32 ch) {
   227     // Note that we cannot use data.lookup() because the
   228     // set array has not been constructed yet.
   229     int32_t i = ch - data->variablesBase;
   230     if (i >= 0 && i < variablesVector->size()) {
   231         UnicodeFunctor *f = (UnicodeFunctor*) variablesVector->elementAt(i);
   232         return f != NULL && f->toMatcher() != NULL;
   233     }
   234     return TRUE;
   235 }
   237 /**
   238  * Return true if the given character is a replacer standin or a plain
   239  * character (non standin).
   240  */
   241 UBool ParseData::isReplacer(UChar32 ch) {
   242     // Note that we cannot use data.lookup() because the
   243     // set array has not been constructed yet.
   244     int i = ch - data->variablesBase;
   245     if (i >= 0 && i < variablesVector->size()) {
   246         UnicodeFunctor *f = (UnicodeFunctor*) variablesVector->elementAt(i);
   247         return f != NULL && f->toReplacer() != NULL;
   248     }
   249     return TRUE;
   250 }
   252 //----------------------------------------------------------------------
   253 // BEGIN RuleHalf
   254 //----------------------------------------------------------------------
   256 /**
   257  * A class representing one side of a rule.  This class knows how to
   258  * parse half of a rule.  It is tightly coupled to the method
   259  * RuleBasedTransliterator.Parser.parseRule().
   260  */
   261 class RuleHalf : public UMemory {
   263 public:
   265     UnicodeString text;
   267     int32_t cursor; // position of cursor in text
   268     int32_t ante;   // position of ante context marker '{' in text
   269     int32_t post;   // position of post context marker '}' in text
   271     // Record the offset to the cursor either to the left or to the
   272     // right of the key.  This is indicated by characters on the output
   273     // side that allow the cursor to be positioned arbitrarily within
   274     // the matching text.  For example, abc{def} > | @@@ xyz; changes
   275     // def to xyz and moves the cursor to before abc.  Offset characters
   276     // must be at the start or end, and they cannot move the cursor past
   277     // the ante- or postcontext text.  Placeholders are only valid in
   278     // output text.  The length of the ante and post context is
   279     // determined at runtime, because of supplementals and quantifiers.
   280     int32_t cursorOffset; // only nonzero on output side
   282     // Position of first CURSOR_OFFSET on _right_.  This will be -1
   283     // for |@, -2 for |@@, etc., and 1 for @|, 2 for @@|, etc.
   284     int32_t cursorOffsetPos;
   286     UBool anchorStart;
   287     UBool anchorEnd;
   289     /**
   290      * The segment number from 1..n of the next '(' we see
   291      * during parsing; 1-based.
   292      */
   293     int32_t nextSegmentNumber;
   295     TransliteratorParser& parser;
   297     //--------------------------------------------------
   298     // Methods
   300     RuleHalf(TransliteratorParser& parser);
   301     ~RuleHalf();
   303     int32_t parse(const UnicodeString& rule, int32_t pos, int32_t limit, UErrorCode& status);
   305     int32_t parseSection(const UnicodeString& rule, int32_t pos, int32_t limit,
   306                          UnicodeString& buf,
   307                          const UnicodeString& illegal,
   308                          UBool isSegment,
   309                          UErrorCode& status);
   311     /**
   312      * Remove context.
   313      */
   314     void removeContext();
   316     /**
   317      * Return true if this half looks like valid output, that is, does not
   318      * contain quantifiers or other special input-only elements.
   319      */
   320     UBool isValidOutput(TransliteratorParser& parser);
   322     /**
   323      * Return true if this half looks like valid input, that is, does not
   324      * contain functions or other special output-only elements.
   325      */
   326     UBool isValidInput(TransliteratorParser& parser);
   328     int syntaxError(UErrorCode code,
   329                     const UnicodeString& rule,
   330                     int32_t start,
   331                     UErrorCode& status) {
   332         return parser.syntaxError(code, rule, start, status);
   333     }
   335 private:
   336     // Disallowed methods; no impl.
   337     RuleHalf(const RuleHalf&);
   338     RuleHalf& operator=(const RuleHalf&);
   339 };
   341 RuleHalf::RuleHalf(TransliteratorParser& p) :
   342     parser(p)
   343 {
   344     cursor = -1;
   345     ante = -1;
   346     post = -1;
   347     cursorOffset = 0;
   348     cursorOffsetPos = 0;
   349     anchorStart = anchorEnd = FALSE;
   350     nextSegmentNumber = 1;
   351 }
   353 RuleHalf::~RuleHalf() {
   354 }
   356 /**
   357  * Parse one side of a rule, stopping at either the limit,
   358  * the END_OF_RULE character, or an operator.
   359  * @return the index after the terminating character, or
   360  * if limit was reached, limit
   361  */
   362 int32_t RuleHalf::parse(const UnicodeString& rule, int32_t pos, int32_t limit, UErrorCode& status) {
   363     int32_t start = pos;
   364     text.truncate(0);
   365     pos = parseSection(rule, pos, limit, text, UnicodeString(TRUE, ILLEGAL_TOP, -1), FALSE, status);
   367     if (cursorOffset > 0 && cursor != cursorOffsetPos) {
   368         return syntaxError(U_MISPLACED_CURSOR_OFFSET, rule, start, status);
   369     }
   371     return pos;
   372 }
   374 /**
   375  * Parse a section of one side of a rule, stopping at either
   376  * the limit, the END_OF_RULE character, an operator, or a
   377  * segment close character.  This method parses both a
   378  * top-level rule half and a segment within such a rule half.
   379  * It calls itself recursively to parse segments and nested
   380  * segments.
   381  * @param buf buffer into which to accumulate the rule pattern
   382  * characters, either literal characters from the rule or
   383  * standins for UnicodeMatcher objects including segments.
   384  * @param illegal the set of special characters that is illegal during
   385  * this parse.
   386  * @param isSegment if true, then we've already seen a '(' and
   387  * pos on entry points right after it.  Accumulate everything
   388  * up to the closing ')', put it in a segment matcher object,
   389  * generate a standin for it, and add the standin to buf.  As
   390  * a side effect, update the segments vector with a reference
   391  * to the segment matcher.  This works recursively for nested
   392  * segments.  If isSegment is false, just accumulate
   393  * characters into buf.
   394  * @return the index after the terminating character, or
   395  * if limit was reached, limit
   396  */
   397 int32_t RuleHalf::parseSection(const UnicodeString& rule, int32_t pos, int32_t limit,
   398                                UnicodeString& buf,
   399                                const UnicodeString& illegal,
   400                                UBool isSegment, UErrorCode& status) {
   401     int32_t start = pos;
   402     ParsePosition pp;
   403     UnicodeString scratch;
   404     UBool done = FALSE;
   405     int32_t quoteStart = -1; // Most recent 'single quoted string'
   406     int32_t quoteLimit = -1;
   407     int32_t varStart = -1; // Most recent $variableReference
   408     int32_t varLimit = -1;
   409     int32_t bufStart = buf.length();
   411     while (pos < limit && !done) {
   412         // Since all syntax characters are in the BMP, fetching
   413         // 16-bit code units suffices here.
   414         UChar c = rule.charAt(pos++);
   415         if (PatternProps::isWhiteSpace(c)) {
   416             // Ignore whitespace.  Note that this is not Unicode
   417             // spaces, but Java spaces -- a subset, representing
   418             // whitespace likely to be seen in code.
   419             continue;
   420         }
   421         if (u_strchr(HALF_ENDERS, c) != NULL) {
   422             if (isSegment) {
   423                 // Unclosed segment
   424                 return syntaxError(U_UNCLOSED_SEGMENT, rule, start, status);
   425             }
   426             break;
   427         }
   428         if (anchorEnd) {
   429             // Text after a presumed end anchor is a syntax err
   430             return syntaxError(U_MALFORMED_VARIABLE_REFERENCE, rule, start, status);
   431         }
   432         if (UnicodeSet::resemblesPattern(rule, pos-1)) {
   433             pp.setIndex(pos-1); // Backup to opening '['
   434             buf.append(parser.parseSet(rule, pp, status));
   435             if (U_FAILURE(status)) {
   436                 return syntaxError(U_MALFORMED_SET, rule, start, status);
   437             }
   438             pos = pp.getIndex();                    
   439             continue;
   440         }
   441         // Handle escapes
   442         if (c == ESCAPE) {
   443             if (pos == limit) {
   444                 return syntaxError(U_TRAILING_BACKSLASH, rule, start, status);
   445             }
   446             UChar32 escaped = rule.unescapeAt(pos); // pos is already past '\\'
   447             if (escaped == (UChar32) -1) {
   448                 return syntaxError(U_MALFORMED_UNICODE_ESCAPE, rule, start, status);
   449             }
   450             if (!parser.checkVariableRange(escaped)) {
   451                 return syntaxError(U_VARIABLE_RANGE_OVERLAP, rule, start, status);
   452             }
   453             buf.append(escaped);
   454             continue;
   455         }
   456         // Handle quoted matter
   457         if (c == QUOTE) {
   458             int32_t iq = rule.indexOf(QUOTE, pos);
   459             if (iq == pos) {
   460                 buf.append(c); // Parse [''] outside quotes as [']
   461                 ++pos;
   462             } else {
   463                 /* This loop picks up a run of quoted text of the
   464                  * form 'aaaa' each time through.  If this run
   465                  * hasn't really ended ('aaaa''bbbb') then it keeps
   466                  * looping, each time adding on a new run.  When it
   467                  * reaches the final quote it breaks.
   468                  */
   469                 quoteStart = buf.length();
   470                 for (;;) {
   471                     if (iq < 0) {
   472                         return syntaxError(U_UNTERMINATED_QUOTE, rule, start, status);
   473                     }
   474                     scratch.truncate(0);
   475                     rule.extractBetween(pos, iq, scratch);
   476                     buf.append(scratch);
   477                     pos = iq+1;
   478                     if (pos < limit && rule.charAt(pos) == QUOTE) {
   479                         // Parse [''] inside quotes as [']
   480                         iq = rule.indexOf(QUOTE, pos+1);
   481                         // Continue looping
   482                     } else {
   483                         break;
   484                     }
   485                 }
   486                 quoteLimit = buf.length();
   488                 for (iq=quoteStart; iq<quoteLimit; ++iq) {
   489                     if (!parser.checkVariableRange(buf.charAt(iq))) {
   490                         return syntaxError(U_VARIABLE_RANGE_OVERLAP, rule, start, status);
   491                     }
   492                 }
   493             }
   494             continue;
   495         }
   497         if (!parser.checkVariableRange(c)) {
   498             return syntaxError(U_VARIABLE_RANGE_OVERLAP, rule, start, status);
   499         }
   501         if (illegal.indexOf(c) >= 0) {
   502             syntaxError(U_ILLEGAL_CHARACTER, rule, start, status);
   503         }
   505         switch (c) {
   507         //------------------------------------------------------
   508         // Elements allowed within and out of segments
   509         //------------------------------------------------------
   510         case ANCHOR_START:
   511             if (buf.length() == 0 && !anchorStart) {
   512                 anchorStart = TRUE;
   513             } else {
   514               return syntaxError(U_MISPLACED_ANCHOR_START,
   515                                  rule, start, status);
   516             }
   517           break;
   518         case SEGMENT_OPEN:
   519             {
   520                 // bufSegStart is the offset in buf to the first
   521                 // character of the segment we are parsing.
   522                 int32_t bufSegStart = buf.length();
   524                 // Record segment number now, since nextSegmentNumber
   525                 // will be incremented during the call to parseSection
   526                 // if there are nested segments.
   527                 int32_t segmentNumber = nextSegmentNumber++; // 1-based
   529                 // Parse the segment
   530                 pos = parseSection(rule, pos, limit, buf, UnicodeString(TRUE, ILLEGAL_SEG, -1), TRUE, status);
   532                 // After parsing a segment, the relevant characters are
   533                 // in buf, starting at offset bufSegStart.  Extract them
   534                 // into a string matcher, and replace them with a
   535                 // standin for that matcher.
   536                 StringMatcher* m =
   537                     new StringMatcher(buf, bufSegStart, buf.length(),
   538                                       segmentNumber, *parser.curData);
   539                 if (m == NULL) {
   540                     return syntaxError(U_MEMORY_ALLOCATION_ERROR, rule, start, status);
   541                 }
   543                 // Record and associate object and segment number
   544                 parser.setSegmentObject(segmentNumber, m, status);
   545                 buf.truncate(bufSegStart);
   546                 buf.append(parser.getSegmentStandin(segmentNumber, status));
   547             }
   548             break;
   549         case FUNCTION:
   550         case ALT_FUNCTION:
   551             {
   552                 int32_t iref = pos;
   553                 TransliteratorIDParser::SingleID* single =
   554                     TransliteratorIDParser::parseFilterID(rule, iref);
   555                 // The next character MUST be a segment open
   556                 if (single == NULL ||
   557                     !ICU_Utility::parseChar(rule, iref, SEGMENT_OPEN)) {
   558                     return syntaxError(U_INVALID_FUNCTION, rule, start, status);
   559                 }
   561                 Transliterator *t = single->createInstance();
   562                 delete single;
   563                 if (t == NULL) {
   564                     return syntaxError(U_INVALID_FUNCTION, rule, start, status);
   565                 }
   567                 // bufSegStart is the offset in buf to the first
   568                 // character of the segment we are parsing.
   569                 int32_t bufSegStart = buf.length();
   571                 // Parse the segment
   572                 pos = parseSection(rule, iref, limit, buf, UnicodeString(TRUE, ILLEGAL_FUNC, -1), TRUE, status);
   574                 // After parsing a segment, the relevant characters are
   575                 // in buf, starting at offset bufSegStart.
   576                 UnicodeString output;
   577                 buf.extractBetween(bufSegStart, buf.length(), output);
   578                 FunctionReplacer *r =
   579                     new FunctionReplacer(t, new StringReplacer(output, parser.curData));
   580                 if (r == NULL) {
   581                     return syntaxError(U_MEMORY_ALLOCATION_ERROR, rule, start, status);
   582                 }
   584                 // Replace the buffer contents with a stand-in
   585                 buf.truncate(bufSegStart);
   586                 buf.append(parser.generateStandInFor(r, status));
   587             }
   588             break;
   589         case SymbolTable::SYMBOL_REF:
   590             // Handle variable references and segment references "$1" .. "$9"
   591             {
   592                 // A variable reference must be followed immediately
   593                 // by a Unicode identifier start and zero or more
   594                 // Unicode identifier part characters, or by a digit
   595                 // 1..9 if it is a segment reference.
   596                 if (pos == limit) {
   597                     // A variable ref character at the end acts as
   598                     // an anchor to the context limit, as in perl.
   599                     anchorEnd = TRUE;
   600                     break;
   601                 }
   602                 // Parse "$1" "$2" .. "$9" .. (no upper limit)
   603                 c = rule.charAt(pos);
   604                 int32_t r = u_digit(c, 10);
   605                 if (r >= 1 && r <= 9) {
   606                     r = ICU_Utility::parseNumber(rule, pos, 10);
   607                     if (r < 0) {
   608                         return syntaxError(U_UNDEFINED_SEGMENT_REFERENCE,
   609                                            rule, start, status);
   610                     }
   611                     buf.append(parser.getSegmentStandin(r, status));
   612                 } else {
   613                     pp.setIndex(pos);
   614                     UnicodeString name = parser.parseData->
   615                                     parseReference(rule, pp, limit);
   616                     if (name.length() == 0) {
   617                         // This means the '$' was not followed by a
   618                         // valid name.  Try to interpret it as an
   619                         // end anchor then.  If this also doesn't work
   620                         // (if we see a following character) then signal
   621                         // an error.
   622                         anchorEnd = TRUE;
   623                         break;
   624                     }
   625                     pos = pp.getIndex();
   626                     // If this is a variable definition statement,
   627                     // then the LHS variable will be undefined.  In
   628                     // that case appendVariableDef() will append the
   629                     // special placeholder char variableLimit-1.
   630                     varStart = buf.length();
   631                     parser.appendVariableDef(name, buf, status);
   632                     varLimit = buf.length();
   633                 }
   634             }
   635             break;
   636         case DOT:
   637             buf.append(parser.getDotStandIn(status));
   638             break;
   639         case KLEENE_STAR:
   640         case ONE_OR_MORE:
   641         case ZERO_OR_ONE:
   642             // Quantifiers.  We handle single characters, quoted strings,
   643             // variable references, and segments.
   644             //  a+      matches  aaa
   645             //  'foo'+  matches  foofoofoo
   646             //  $v+     matches  xyxyxy if $v == xy
   647             //  (seg)+  matches  segsegseg
   648             {
   649                 if (isSegment && buf.length() == bufStart) {
   650                     // The */+ immediately follows '('
   651                     return syntaxError(U_MISPLACED_QUANTIFIER, rule, start, status);
   652                 }
   654                 int32_t qstart, qlimit;
   655                 // The */+ follows an isolated character or quote
   656                 // or variable reference
   657                 if (buf.length() == quoteLimit) {
   658                     // The */+ follows a 'quoted string'
   659                     qstart = quoteStart;
   660                     qlimit = quoteLimit;
   661                 } else if (buf.length() == varLimit) {
   662                     // The */+ follows a $variableReference
   663                     qstart = varStart;
   664                     qlimit = varLimit;
   665                 } else {
   666                     // The */+ follows a single character, possibly
   667                     // a segment standin
   668                     qstart = buf.length() - 1;
   669                     qlimit = qstart + 1;
   670                 }
   672                 UnicodeFunctor *m =
   673                     new StringMatcher(buf, qstart, qlimit, 0, *parser.curData);
   674                 if (m == NULL) {
   675                     return syntaxError(U_MEMORY_ALLOCATION_ERROR, rule, start, status);
   676                 }
   677                 int32_t min = 0;
   678                 int32_t max = Quantifier::MAX;
   679                 switch (c) {
   680                 case ONE_OR_MORE:
   681                     min = 1;
   682                     break;
   683                 case ZERO_OR_ONE:
   684                     min = 0;
   685                     max = 1;
   686                     break;
   687                 // case KLEENE_STAR:
   688                 //    do nothing -- min, max already set
   689                 }
   690                 m = new Quantifier(m, min, max);
   691                 if (m == NULL) {
   692                     return syntaxError(U_MEMORY_ALLOCATION_ERROR, rule, start, status);
   693                 }
   694                 buf.truncate(qstart);
   695                 buf.append(parser.generateStandInFor(m, status));
   696             }
   697             break;
   699         //------------------------------------------------------
   700         // Elements allowed ONLY WITHIN segments
   701         //------------------------------------------------------
   702         case SEGMENT_CLOSE:
   703             // assert(isSegment);
   704             // We're done parsing a segment.
   705             done = TRUE;
   706             break;
   708         //------------------------------------------------------
   709         // Elements allowed ONLY OUTSIDE segments
   710         //------------------------------------------------------
   711         case CONTEXT_ANTE:
   712             if (ante >= 0) {
   713                 return syntaxError(U_MULTIPLE_ANTE_CONTEXTS, rule, start, status);
   714             }
   715             ante = buf.length();
   716             break;
   717         case CONTEXT_POST:
   718             if (post >= 0) {
   719                 return syntaxError(U_MULTIPLE_POST_CONTEXTS, rule, start, status);
   720             }
   721             post = buf.length();
   722             break;
   723         case CURSOR_POS:
   724             if (cursor >= 0) {
   725                 return syntaxError(U_MULTIPLE_CURSORS, rule, start, status);
   726             }
   727             cursor = buf.length();
   728             break;
   729         case CURSOR_OFFSET:
   730             if (cursorOffset < 0) {
   731                 if (buf.length() > 0) {
   732                     return syntaxError(U_MISPLACED_CURSOR_OFFSET, rule, start, status);
   733                 }
   734                 --cursorOffset;
   735             } else if (cursorOffset > 0) {
   736                 if (buf.length() != cursorOffsetPos || cursor >= 0) {
   737                     return syntaxError(U_MISPLACED_CURSOR_OFFSET, rule, start, status);
   738                 }
   739                 ++cursorOffset;
   740             } else {
   741                 if (cursor == 0 && buf.length() == 0) {
   742                     cursorOffset = -1;
   743                 } else if (cursor < 0) {
   744                     cursorOffsetPos = buf.length();
   745                     cursorOffset = 1;
   746                 } else {
   747                     return syntaxError(U_MISPLACED_CURSOR_OFFSET, rule, start, status);
   748                 }
   749             }
   750             break;
   753         //------------------------------------------------------
   754         // Non-special characters
   755         //------------------------------------------------------
   756         default:
   757             // Disallow unquoted characters other than [0-9A-Za-z]
   758             // in the printable ASCII range.  These characters are
   759             // reserved for possible future use.
   760             if (c >= 0x0021 && c <= 0x007E &&
   761                 !((c >= 0x0030/*'0'*/ && c <= 0x0039/*'9'*/) ||
   762                   (c >= 0x0041/*'A'*/ && c <= 0x005A/*'Z'*/) ||
   763                   (c >= 0x0061/*'a'*/ && c <= 0x007A/*'z'*/))) {
   764                 return syntaxError(U_UNQUOTED_SPECIAL, rule, start, status);
   765             }
   766             buf.append(c);
   767             break;
   768         }
   769     }
   771     return pos;
   772 }
   774 /**
   775  * Remove context.
   776  */
   777 void RuleHalf::removeContext() {
   778     //text = text.substring(ante < 0 ? 0 : ante,
   779     //                      post < 0 ? text.length() : post);
   780     if (post >= 0) {
   781         text.remove(post);
   782     }
   783     if (ante >= 0) {
   784         text.removeBetween(0, ante);
   785     }
   786     ante = post = -1;
   787     anchorStart = anchorEnd = FALSE;
   788 }
   790 /**
   791  * Return true if this half looks like valid output, that is, does not
   792  * contain quantifiers or other special input-only elements.
   793  */
   794 UBool RuleHalf::isValidOutput(TransliteratorParser& transParser) {
   795     for (int32_t i=0; i<text.length(); ) {
   796         UChar32 c = text.char32At(i);
   797         i += U16_LENGTH(c);
   798         if (!transParser.parseData->isReplacer(c)) {
   799             return FALSE;
   800         }
   801     }
   802     return TRUE;
   803 }
   805 /**
   806  * Return true if this half looks like valid input, that is, does not
   807  * contain functions or other special output-only elements.
   808  */
   809 UBool RuleHalf::isValidInput(TransliteratorParser& transParser) {
   810     for (int32_t i=0; i<text.length(); ) {
   811         UChar32 c = text.char32At(i);
   812         i += U16_LENGTH(c);
   813         if (!transParser.parseData->isMatcher(c)) {
   814             return FALSE;
   815         }
   816     }
   817     return TRUE;
   818 }
   820 //----------------------------------------------------------------------
   821 // PUBLIC API
   822 //----------------------------------------------------------------------
   824 /**
   825  * Constructor.
   826  */
   827 TransliteratorParser::TransliteratorParser(UErrorCode &statusReturn) :
   828 dataVector(statusReturn),
   829 idBlockVector(statusReturn),
   830 variablesVector(statusReturn),
   831 segmentObjects(statusReturn)
   832 {
   833     idBlockVector.setDeleter(uprv_deleteUObject);
   834     curData = NULL;
   835     compoundFilter = NULL;
   836     parseData = NULL;
   837     variableNames.setValueDeleter(uprv_deleteUObject);
   838 }
   840 /**
   841  * Destructor.
   842  */
   843 TransliteratorParser::~TransliteratorParser() {
   844     while (!dataVector.isEmpty())
   845         delete (TransliterationRuleData*)(dataVector.orphanElementAt(0));
   846     delete compoundFilter;
   847     delete parseData;
   848     while (!variablesVector.isEmpty())
   849         delete (UnicodeFunctor*)variablesVector.orphanElementAt(0);
   850 }
   852 void
   853 TransliteratorParser::parse(const UnicodeString& rules,
   854                             UTransDirection transDirection,
   855                             UParseError& pe,
   856                             UErrorCode& ec) {
   857     if (U_SUCCESS(ec)) {
   858         parseRules(rules, transDirection, ec);
   859         pe = parseError;
   860     }
   861 }
   863 /**
   864  * Return the compound filter parsed by parse().  Caller owns result.
   865  */ 
   866 UnicodeSet* TransliteratorParser::orphanCompoundFilter() {
   867     UnicodeSet* f = compoundFilter;
   868     compoundFilter = NULL;
   869     return f;
   870 }
   872 //----------------------------------------------------------------------
   873 // Private implementation
   874 //----------------------------------------------------------------------
   876 /**
   877  * Parse the given string as a sequence of rules, separated by newline
   878  * characters ('\n'), and cause this object to implement those rules.  Any
   879  * previous rules are discarded.  Typically this method is called exactly
   880  * once, during construction.
   881  * @exception IllegalArgumentException if there is a syntax error in the
   882  * rules
   883  */
   884 void TransliteratorParser::parseRules(const UnicodeString& rule,
   885                                       UTransDirection theDirection,
   886                                       UErrorCode& status)
   887 {
   888     // Clear error struct
   889     uprv_memset(&parseError, 0, sizeof(parseError));
   890     parseError.line = parseError.offset = -1;
   892     UBool parsingIDs = TRUE;
   893     int32_t ruleCount = 0;
   895     while (!dataVector.isEmpty()) {
   896         delete (TransliterationRuleData*)(dataVector.orphanElementAt(0));
   897     }
   898     if (U_FAILURE(status)) {
   899         return;
   900     }
   902     idBlockVector.removeAllElements();
   903     curData = NULL;
   904     direction = theDirection;
   905     ruleCount = 0;
   907     delete compoundFilter;
   908     compoundFilter = NULL;
   910     while (!variablesVector.isEmpty()) {
   911         delete (UnicodeFunctor*)variablesVector.orphanElementAt(0);
   912     }
   913     variableNames.removeAll();
   914     parseData = new ParseData(0, &variablesVector, &variableNames);
   915     if (parseData == NULL) {
   916         status = U_MEMORY_ALLOCATION_ERROR;
   917         return;
   918     }
   920     dotStandIn = (UChar) -1;
   922     UnicodeString *tempstr = NULL; // used for memory allocation error checking
   923     UnicodeString str; // scratch
   924     UnicodeString idBlockResult;
   925     int32_t pos = 0;
   926     int32_t limit = rule.length();
   928     // The compound filter offset is an index into idBlockResult.
   929     // If it is 0, then the compound filter occurred at the start,
   930     // and it is the offset to the _start_ of the compound filter
   931     // pattern.  Otherwise it is the offset to the _limit_ of the
   932     // compound filter pattern within idBlockResult.
   933     compoundFilter = NULL;
   934     int32_t compoundFilterOffset = -1;
   936     while (pos < limit && U_SUCCESS(status)) {
   937         UChar c = rule.charAt(pos++);
   938         if (PatternProps::isWhiteSpace(c)) {
   939             // Ignore leading whitespace.
   940             continue;
   941         }
   942         // Skip lines starting with the comment character
   943         if (c == RULE_COMMENT_CHAR) {
   944             pos = rule.indexOf((UChar)0x000A /*\n*/, pos) + 1;
   945             if (pos == 0) {
   946                 break; // No "\n" found; rest of rule is a commnet
   947             }
   948             continue; // Either fall out or restart with next line
   949         }
   951         // skip empty rules
   952         if (c == END_OF_RULE)
   953             continue;
   955         // keep track of how many rules we've seen
   956         ++ruleCount;
   958         // We've found the start of a rule or ID.  c is its first
   959         // character, and pos points past c.
   960         --pos;
   961         // Look for an ID token.  Must have at least ID_TOKEN_LEN + 1
   962         // chars left.
   963         if ((pos + ID_TOKEN_LEN + 1) <= limit &&
   964                 rule.compare(pos, ID_TOKEN_LEN, ID_TOKEN) == 0) {
   965             pos += ID_TOKEN_LEN;
   966             c = rule.charAt(pos);
   967             while (PatternProps::isWhiteSpace(c) && pos < limit) {
   968                 ++pos;
   969                 c = rule.charAt(pos);
   970             }
   972             int32_t p = pos;
   974             if (!parsingIDs) {
   975                 if (curData != NULL) {
   976                     if (direction == UTRANS_FORWARD)
   977                         dataVector.addElement(curData, status);
   978                     else
   979                         dataVector.insertElementAt(curData, 0, status);
   980                     curData = NULL;
   981                 }
   982                 parsingIDs = TRUE;
   983             }
   985             TransliteratorIDParser::SingleID* id =
   986                 TransliteratorIDParser::parseSingleID(rule, p, direction, status);
   987             if (p != pos && ICU_Utility::parseChar(rule, p, END_OF_RULE)) {
   988                 // Successful ::ID parse.
   990                 if (direction == UTRANS_FORWARD) {
   991                     idBlockResult.append(id->canonID).append(END_OF_RULE);
   992                 } else {
   993                     idBlockResult.insert(0, END_OF_RULE);
   994                     idBlockResult.insert(0, id->canonID);
   995                 }
   997             } else {
   998                 // Couldn't parse an ID.  Try to parse a global filter
   999                 int32_t withParens = -1;
  1000                 UnicodeSet* f = TransliteratorIDParser::parseGlobalFilter(rule, p, direction, withParens, NULL);
  1001                 if (f != NULL) {
  1002                     if (ICU_Utility::parseChar(rule, p, END_OF_RULE)
  1003                         && (direction == UTRANS_FORWARD) == (withParens == 0))
  1005                         if (compoundFilter != NULL) {
  1006                             // Multiple compound filters
  1007                             syntaxError(U_MULTIPLE_COMPOUND_FILTERS, rule, pos, status);
  1008                             delete f;
  1009                         } else {
  1010                             compoundFilter = f;
  1011                             compoundFilterOffset = ruleCount;
  1013                     } else {
  1014                         delete f;
  1016                 } else {
  1017                     // Invalid ::id
  1018                     // Can be parsed as neither an ID nor a global filter
  1019                     syntaxError(U_INVALID_ID, rule, pos, status);
  1022             delete id;
  1023             pos = p;
  1024         } else {
  1025             if (parsingIDs) {
  1026                 tempstr = new UnicodeString(idBlockResult);
  1027                 // NULL pointer check
  1028                 if (tempstr == NULL) {
  1029                     status = U_MEMORY_ALLOCATION_ERROR;
  1030                     return;
  1032                 if (direction == UTRANS_FORWARD)
  1033                     idBlockVector.addElement(tempstr, status);
  1034                 else
  1035                     idBlockVector.insertElementAt(tempstr, 0, status);
  1036                 idBlockResult.remove();
  1037                 parsingIDs = FALSE;
  1038                 curData = new TransliterationRuleData(status);
  1039                 // NULL pointer check
  1040                 if (curData == NULL) {
  1041                     status = U_MEMORY_ALLOCATION_ERROR;
  1042                     return;
  1044                 parseData->data = curData;
  1046                 // By default, rules use part of the private use area
  1047                 // E000..F8FF for variables and other stand-ins.  Currently
  1048                 // the range F000..F8FF is typically sufficient.  The 'use
  1049                 // variable range' pragma allows rule sets to modify this.
  1050                 setVariableRange(0xF000, 0xF8FF, status);
  1053             if (resemblesPragma(rule, pos, limit)) {
  1054                 int32_t ppp = parsePragma(rule, pos, limit, status);
  1055                 if (ppp < 0) {
  1056                     syntaxError(U_MALFORMED_PRAGMA, rule, pos, status);
  1058                 pos = ppp;
  1059             // Parse a rule
  1060             } else {
  1061                 pos = parseRule(rule, pos, limit, status);
  1066     if (parsingIDs && idBlockResult.length() > 0) {
  1067         tempstr = new UnicodeString(idBlockResult);
  1068         // NULL pointer check
  1069         if (tempstr == NULL) {
  1070             status = U_MEMORY_ALLOCATION_ERROR;
  1071             return;
  1073         if (direction == UTRANS_FORWARD)
  1074             idBlockVector.addElement(tempstr, status);
  1075         else
  1076             idBlockVector.insertElementAt(tempstr, 0, status);
  1078     else if (!parsingIDs && curData != NULL) {
  1079         if (direction == UTRANS_FORWARD)
  1080             dataVector.addElement(curData, status);
  1081         else
  1082             dataVector.insertElementAt(curData, 0, status);
  1085     if (U_SUCCESS(status)) {
  1086         // Convert the set vector to an array
  1087         int32_t i, dataVectorSize = dataVector.size();
  1088         for (i = 0; i < dataVectorSize; i++) {
  1089             TransliterationRuleData* data = (TransliterationRuleData*)dataVector.elementAt(i);
  1090             data->variablesLength = variablesVector.size();
  1091             if (data->variablesLength == 0) {
  1092                 data->variables = 0;
  1093             } else {
  1094                 data->variables = (UnicodeFunctor**)uprv_malloc(data->variablesLength * sizeof(UnicodeFunctor*));
  1095                 // NULL pointer check
  1096                 if (data->variables == NULL) {
  1097                     status = U_MEMORY_ALLOCATION_ERROR;
  1098                     return;
  1100                 data->variablesAreOwned = (i == 0);
  1103             for (int32_t j = 0; j < data->variablesLength; j++) {
  1104                 data->variables[j] =
  1105                     ((UnicodeSet*)variablesVector.elementAt(j));
  1108             data->variableNames.removeAll();
  1109             int32_t pos = -1;
  1110             const UHashElement* he = variableNames.nextElement(pos);
  1111             while (he != NULL) {
  1112                 UnicodeString* tempus = (UnicodeString*)(((UnicodeString*)(he->value.pointer))->clone());
  1113                 if (tempus == NULL) {
  1114                     status = U_MEMORY_ALLOCATION_ERROR;
  1115                     return;
  1117                 data->variableNames.put(*((UnicodeString*)(he->key.pointer)),
  1118                     tempus, status);
  1119                 he = variableNames.nextElement(pos);
  1122         variablesVector.removeAllElements();   // keeps them from getting deleted when we succeed
  1124         // Index the rules
  1125         if (compoundFilter != NULL) {
  1126             if ((direction == UTRANS_FORWARD && compoundFilterOffset != 1) ||
  1127                 (direction == UTRANS_REVERSE && compoundFilterOffset != ruleCount)) {
  1128                 status = U_MISPLACED_COMPOUND_FILTER;
  1132         for (i = 0; i < dataVectorSize; i++) {
  1133             TransliterationRuleData* data = (TransliterationRuleData*)dataVector.elementAt(i);
  1134             data->ruleSet.freeze(parseError, status);
  1136         if (idBlockVector.size() == 1 && ((UnicodeString*)idBlockVector.elementAt(0))->isEmpty()) {
  1137             idBlockVector.removeElementAt(0);
  1142 /**
  1143  * Set the variable range to [start, end] (inclusive).
  1144  */
  1145 void TransliteratorParser::setVariableRange(int32_t start, int32_t end, UErrorCode& status) {
  1146     if (start > end || start < 0 || end > 0xFFFF) {
  1147         status = U_MALFORMED_PRAGMA;
  1148         return;
  1151     curData->variablesBase = (UChar) start;
  1152     if (dataVector.size() == 0) {
  1153         variableNext = (UChar) start;
  1154         variableLimit = (UChar) (end + 1);
  1158 /**
  1159  * Assert that the given character is NOT within the variable range.
  1160  * If it is, return FALSE.  This is neccesary to ensure that the
  1161  * variable range does not overlap characters used in a rule.
  1162  */
  1163 UBool TransliteratorParser::checkVariableRange(UChar32 ch) const {
  1164     return !(ch >= curData->variablesBase && ch < variableLimit);
  1167 /**
  1168  * Set the maximum backup to 'backup', in response to a pragma
  1169  * statement.
  1170  */
  1171 void TransliteratorParser::pragmaMaximumBackup(int32_t /*backup*/) {
  1172     //TODO Finish
  1175 /**
  1176  * Begin normalizing all rules using the given mode, in response
  1177  * to a pragma statement.
  1178  */
  1179 void TransliteratorParser::pragmaNormalizeRules(UNormalizationMode /*mode*/) {
  1180     //TODO Finish
  1183 static const UChar PRAGMA_USE[] = {0x75,0x73,0x65,0x20,0}; // "use "
  1185 static const UChar PRAGMA_VARIABLE_RANGE[] = {0x7E,0x76,0x61,0x72,0x69,0x61,0x62,0x6C,0x65,0x20,0x72,0x61,0x6E,0x67,0x65,0x20,0x23,0x20,0x23,0x7E,0x3B,0}; // "~variable range # #~;"
  1187 static const UChar PRAGMA_MAXIMUM_BACKUP[] = {0x7E,0x6D,0x61,0x78,0x69,0x6D,0x75,0x6D,0x20,0x62,0x61,0x63,0x6B,0x75,0x70,0x20,0x23,0x7E,0x3B,0}; // "~maximum backup #~;"
  1189 static const UChar PRAGMA_NFD_RULES[] = {0x7E,0x6E,0x66,0x64,0x20,0x72,0x75,0x6C,0x65,0x73,0x7E,0x3B,0}; // "~nfd rules~;"
  1191 static const UChar PRAGMA_NFC_RULES[] = {0x7E,0x6E,0x66,0x63,0x20,0x72,0x75,0x6C,0x65,0x73,0x7E,0x3B,0}; // "~nfc rules~;"
  1193 /**
  1194  * Return true if the given rule looks like a pragma.
  1195  * @param pos offset to the first non-whitespace character
  1196  * of the rule.
  1197  * @param limit pointer past the last character of the rule.
  1198  */
  1199 UBool TransliteratorParser::resemblesPragma(const UnicodeString& rule, int32_t pos, int32_t limit) {
  1200     // Must start with /use\s/i
  1201     return ICU_Utility::parsePattern(rule, pos, limit, UnicodeString(TRUE, PRAGMA_USE, 4), NULL) >= 0;
  1204 /**
  1205  * Parse a pragma.  This method assumes resemblesPragma() has
  1206  * already returned true.
  1207  * @param pos offset to the first non-whitespace character
  1208  * of the rule.
  1209  * @param limit pointer past the last character of the rule.
  1210  * @return the position index after the final ';' of the pragma,
  1211  * or -1 on failure.
  1212  */
  1213 int32_t TransliteratorParser::parsePragma(const UnicodeString& rule, int32_t pos, int32_t limit, UErrorCode& status) {
  1214     int32_t array[2];
  1216     // resemblesPragma() has already returned true, so we
  1217     // know that pos points to /use\s/i; we can skip 4 characters
  1218     // immediately
  1219     pos += 4;
  1221     // Here are the pragmas we recognize:
  1222     // use variable range 0xE000 0xEFFF;
  1223     // use maximum backup 16;
  1224     // use nfd rules;
  1225     // use nfc rules;
  1226     int p = ICU_Utility::parsePattern(rule, pos, limit, UnicodeString(TRUE, PRAGMA_VARIABLE_RANGE, -1), array);
  1227     if (p >= 0) {
  1228         setVariableRange(array[0], array[1], status);
  1229         return p;
  1232     p = ICU_Utility::parsePattern(rule, pos, limit, UnicodeString(TRUE, PRAGMA_MAXIMUM_BACKUP, -1), array);
  1233     if (p >= 0) {
  1234         pragmaMaximumBackup(array[0]);
  1235         return p;
  1238     p = ICU_Utility::parsePattern(rule, pos, limit, UnicodeString(TRUE, PRAGMA_NFD_RULES, -1), NULL);
  1239     if (p >= 0) {
  1240         pragmaNormalizeRules(UNORM_NFD);
  1241         return p;
  1244     p = ICU_Utility::parsePattern(rule, pos, limit, UnicodeString(TRUE, PRAGMA_NFC_RULES, -1), NULL);
  1245     if (p >= 0) {
  1246         pragmaNormalizeRules(UNORM_NFC);
  1247         return p;
  1250     // Syntax error: unable to parse pragma
  1251     return -1;
  1254 /**
  1255  * MAIN PARSER.  Parse the next rule in the given rule string, starting
  1256  * at pos.  Return the index after the last character parsed.  Do not
  1257  * parse characters at or after limit.
  1259  * Important:  The character at pos must be a non-whitespace character
  1260  * that is not the comment character.
  1262  * This method handles quoting, escaping, and whitespace removal.  It
  1263  * parses the end-of-rule character.  It recognizes context and cursor
  1264  * indicators.  Once it does a lexical breakdown of the rule at pos, it
  1265  * creates a rule object and adds it to our rule list.
  1266  */
  1267 int32_t TransliteratorParser::parseRule(const UnicodeString& rule, int32_t pos, int32_t limit, UErrorCode& status) {
  1268     // Locate the left side, operator, and right side
  1269     int32_t start = pos;
  1270     UChar op = 0;
  1271     int32_t i;
  1273     // Set up segments data
  1274     segmentStandins.truncate(0);
  1275     segmentObjects.removeAllElements();
  1277     // Use pointers to automatics to make swapping possible.
  1278     RuleHalf _left(*this), _right(*this);
  1279     RuleHalf* left = &_left;
  1280     RuleHalf* right = &_right;
  1282     undefinedVariableName.remove();
  1283     pos = left->parse(rule, pos, limit, status);
  1284     if (U_FAILURE(status)) {
  1285         return start;
  1288     if (pos == limit || u_strchr(gOPERATORS, (op = rule.charAt(--pos))) == NULL) {
  1289         return syntaxError(U_MISSING_OPERATOR, rule, start, status);
  1291     ++pos;
  1293     // Found an operator char.  Check for forward-reverse operator.
  1294     if (op == REVERSE_RULE_OP &&
  1295         (pos < limit && rule.charAt(pos) == FORWARD_RULE_OP)) {
  1296         ++pos;
  1297         op = FWDREV_RULE_OP;
  1300     // Translate alternate op characters.
  1301     switch (op) {
  1302     case ALT_FORWARD_RULE_OP:
  1303         op = FORWARD_RULE_OP;
  1304         break;
  1305     case ALT_REVERSE_RULE_OP:
  1306         op = REVERSE_RULE_OP;
  1307         break;
  1308     case ALT_FWDREV_RULE_OP:
  1309         op = FWDREV_RULE_OP;
  1310         break;
  1313     pos = right->parse(rule, pos, limit, status);
  1314     if (U_FAILURE(status)) {
  1315         return start;
  1318     if (pos < limit) {
  1319         if (rule.charAt(--pos) == END_OF_RULE) {
  1320             ++pos;
  1321         } else {
  1322             // RuleHalf parser must have terminated at an operator
  1323             return syntaxError(U_UNQUOTED_SPECIAL, rule, start, status);
  1327     if (op == VARIABLE_DEF_OP) {
  1328         // LHS is the name.  RHS is a single character, either a literal
  1329         // or a set (already parsed).  If RHS is longer than one
  1330         // character, it is either a multi-character string, or multiple
  1331         // sets, or a mixture of chars and sets -- syntax error.
  1333         // We expect to see a single undefined variable (the one being
  1334         // defined).
  1335         if (undefinedVariableName.length() == 0) {
  1336             // "Missing '$' or duplicate definition"
  1337             return syntaxError(U_BAD_VARIABLE_DEFINITION, rule, start, status);
  1339         if (left->text.length() != 1 || left->text.charAt(0) != variableLimit) {
  1340             // "Malformed LHS"
  1341             return syntaxError(U_MALFORMED_VARIABLE_DEFINITION, rule, start, status);
  1343         if (left->anchorStart || left->anchorEnd ||
  1344             right->anchorStart || right->anchorEnd) {
  1345             return syntaxError(U_MALFORMED_VARIABLE_DEFINITION, rule, start, status);
  1347         // We allow anything on the right, including an empty string.
  1348         UnicodeString* value = new UnicodeString(right->text);
  1349         // NULL pointer check
  1350         if (value == NULL) {
  1351             return syntaxError(U_MEMORY_ALLOCATION_ERROR, rule, start, status);
  1353         variableNames.put(undefinedVariableName, value, status);
  1354         ++variableLimit;
  1355         return pos;
  1358     // If this is not a variable definition rule, we shouldn't have
  1359     // any undefined variable names.
  1360     if (undefinedVariableName.length() != 0) {
  1361         return syntaxError(// "Undefined variable $" + undefinedVariableName,
  1362                     U_UNDEFINED_VARIABLE,
  1363                     rule, start, status);
  1366     // Verify segments
  1367     if (segmentStandins.length() > segmentObjects.size()) {
  1368         syntaxError(U_UNDEFINED_SEGMENT_REFERENCE, rule, start, status);
  1370     for (i=0; i<segmentStandins.length(); ++i) {
  1371         if (segmentStandins.charAt(i) == 0) {
  1372             syntaxError(U_INTERNAL_TRANSLITERATOR_ERROR, rule, start, status); // will never happen
  1375     for (i=0; i<segmentObjects.size(); ++i) {
  1376         if (segmentObjects.elementAt(i) == NULL) {
  1377             syntaxError(U_INTERNAL_TRANSLITERATOR_ERROR, rule, start, status); // will never happen
  1381     // If the direction we want doesn't match the rule
  1382     // direction, do nothing.
  1383     if (op != FWDREV_RULE_OP &&
  1384         ((direction == UTRANS_FORWARD) != (op == FORWARD_RULE_OP))) {
  1385         return pos;
  1388     // Transform the rule into a forward rule by swapping the
  1389     // sides if necessary.
  1390     if (direction == UTRANS_REVERSE) {
  1391         left = &_right;
  1392         right = &_left;
  1395     // Remove non-applicable elements in forward-reverse
  1396     // rules.  Bidirectional rules ignore elements that do not
  1397     // apply.
  1398     if (op == FWDREV_RULE_OP) {
  1399         right->removeContext();
  1400         left->cursor = -1;
  1401         left->cursorOffset = 0;
  1404     // Normalize context
  1405     if (left->ante < 0) {
  1406         left->ante = 0;
  1408     if (left->post < 0) {
  1409         left->post = left->text.length();
  1412     // Context is only allowed on the input side.  Cursors are only
  1413     // allowed on the output side.  Segment delimiters can only appear
  1414     // on the left, and references on the right.  Cursor offset
  1415     // cannot appear without an explicit cursor.  Cursor offset
  1416     // cannot place the cursor outside the limits of the context.
  1417     // Anchors are only allowed on the input side.
  1418     if (right->ante >= 0 || right->post >= 0 || left->cursor >= 0 ||
  1419         (right->cursorOffset != 0 && right->cursor < 0) ||
  1420         // - The following two checks were used to ensure that the
  1421         // - the cursor offset stayed within the ante- or postcontext.
  1422         // - However, with the addition of quantifiers, we have to
  1423         // - allow arbitrary cursor offsets and do runtime checking.
  1424         //(right->cursorOffset > (left->text.length() - left->post)) ||
  1425         //(-right->cursorOffset > left->ante) ||
  1426         right->anchorStart || right->anchorEnd ||
  1427         !left->isValidInput(*this) || !right->isValidOutput(*this) ||
  1428         left->ante > left->post) {
  1430         return syntaxError(U_MALFORMED_RULE, rule, start, status);
  1433     // Flatten segment objects vector to an array
  1434     UnicodeFunctor** segmentsArray = NULL;
  1435     if (segmentObjects.size() > 0) {
  1436         segmentsArray = (UnicodeFunctor **)uprv_malloc(segmentObjects.size() * sizeof(UnicodeFunctor *));
  1437         // Null pointer check
  1438         if (segmentsArray == NULL) {
  1439             return syntaxError(U_MEMORY_ALLOCATION_ERROR, rule, start, status);
  1441         segmentObjects.toArray((void**) segmentsArray);
  1443     TransliterationRule* temptr = new TransliterationRule(
  1444             left->text, left->ante, left->post,
  1445             right->text, right->cursor, right->cursorOffset,
  1446             segmentsArray,
  1447             segmentObjects.size(),
  1448             left->anchorStart, left->anchorEnd,
  1449             curData,
  1450             status);
  1451     //Null pointer check
  1452     if (temptr == NULL) {
  1453         uprv_free(segmentsArray);
  1454         return syntaxError(U_MEMORY_ALLOCATION_ERROR, rule, start, status);
  1457     curData->ruleSet.addRule(temptr, status);
  1459     return pos;
  1462 /**
  1463  * Called by main parser upon syntax error.  Search the rule string
  1464  * for the probable end of the rule.  Of course, if the error is that
  1465  * the end of rule marker is missing, then the rule end will not be found.
  1466  * In any case the rule start will be correctly reported.
  1467  * @param msg error description
  1468  * @param rule pattern string
  1469  * @param start position of first character of current rule
  1470  */
  1471 int32_t TransliteratorParser::syntaxError(UErrorCode parseErrorCode,
  1472                                           const UnicodeString& rule,
  1473                                           int32_t pos,
  1474                                           UErrorCode& status)
  1476     parseError.offset = pos;
  1477     parseError.line = 0 ; /* we are not using line numbers */
  1479     // for pre-context
  1480     const int32_t LEN = U_PARSE_CONTEXT_LEN - 1;
  1481     int32_t start = uprv_max(pos - LEN, 0);
  1482     int32_t stop  = pos;
  1484     rule.extract(start,stop-start,parseError.preContext);
  1485     //null terminate the buffer
  1486     parseError.preContext[stop-start] = 0;
  1488     //for post-context
  1489     start = pos;
  1490     stop  = uprv_min(pos + LEN, rule.length());
  1492     rule.extract(start,stop-start,parseError.postContext);
  1493     //null terminate the buffer
  1494     parseError.postContext[stop-start]= 0;
  1496     status = (UErrorCode)parseErrorCode;
  1497     return pos;
  1501 /**
  1502  * Parse a UnicodeSet out, store it, and return the stand-in character
  1503  * used to represent it.
  1504  */
  1505 UChar TransliteratorParser::parseSet(const UnicodeString& rule,
  1506                                           ParsePosition& pos,
  1507                                           UErrorCode& status) {
  1508     UnicodeSet* set = new UnicodeSet(rule, pos, USET_IGNORE_SPACE, parseData, status);
  1509     // Null pointer check
  1510     if (set == NULL) {
  1511         status = U_MEMORY_ALLOCATION_ERROR;
  1512         return (UChar)0x0000; // Return empty character with error.
  1514     set->compact();
  1515     return generateStandInFor(set, status);
  1518 /**
  1519  * Generate and return a stand-in for a new UnicodeFunctor.  Store
  1520  * the matcher (adopt it).
  1521  */
  1522 UChar TransliteratorParser::generateStandInFor(UnicodeFunctor* adopted, UErrorCode& status) {
  1523     // assert(obj != null);
  1525     // Look up previous stand-in, if any.  This is a short list
  1526     // (typical n is 0, 1, or 2); linear search is optimal.
  1527     for (int32_t i=0; i<variablesVector.size(); ++i) {
  1528         if (variablesVector.elementAt(i) == adopted) { // [sic] pointer comparison
  1529             return (UChar) (curData->variablesBase + i);
  1533     if (variableNext >= variableLimit) {
  1534         delete adopted;
  1535         status = U_VARIABLE_RANGE_EXHAUSTED;
  1536         return 0;
  1538     variablesVector.addElement(adopted, status);
  1539     return variableNext++;
  1542 /**
  1543  * Return the standin for segment seg (1-based).
  1544  */
  1545 UChar TransliteratorParser::getSegmentStandin(int32_t seg, UErrorCode& status) {
  1546     // Special character used to indicate an empty spot
  1547     UChar empty = curData->variablesBase - 1;
  1548     while (segmentStandins.length() < seg) {
  1549         segmentStandins.append(empty);
  1551     UChar c = segmentStandins.charAt(seg-1);
  1552     if (c == empty) {
  1553         if (variableNext >= variableLimit) {
  1554             status = U_VARIABLE_RANGE_EXHAUSTED;
  1555             return 0;
  1557         c = variableNext++;
  1558         // Set a placeholder in the master variables vector that will be
  1559         // filled in later by setSegmentObject().  We know that we will get
  1560         // called first because setSegmentObject() will call us.
  1561         variablesVector.addElement((void*) NULL, status);
  1562         segmentStandins.setCharAt(seg-1, c);
  1564     return c;
  1567 /**
  1568  * Set the object for segment seg (1-based).
  1569  */
  1570 void TransliteratorParser::setSegmentObject(int32_t seg, StringMatcher* adopted, UErrorCode& status) {
  1571     // Since we call parseSection() recursively, nested
  1572     // segments will result in segment i+1 getting parsed
  1573     // and stored before segment i; be careful with the
  1574     // vector handling here.
  1575     if (segmentObjects.size() < seg) {
  1576         segmentObjects.setSize(seg, status);
  1578     int32_t index = getSegmentStandin(seg, status) - curData->variablesBase;
  1579     if (segmentObjects.elementAt(seg-1) != NULL ||
  1580         variablesVector.elementAt(index) != NULL) {
  1581         // should never happen
  1582         status = U_INTERNAL_TRANSLITERATOR_ERROR;
  1583         return;
  1585     segmentObjects.setElementAt(adopted, seg-1);
  1586     variablesVector.setElementAt(adopted, index);
  1589 /**
  1590  * Return the stand-in for the dot set.  It is allocated the first
  1591  * time and reused thereafter.
  1592  */
  1593 UChar TransliteratorParser::getDotStandIn(UErrorCode& status) {
  1594     if (dotStandIn == (UChar) -1) {
  1595         UnicodeSet* tempus = new UnicodeSet(UnicodeString(TRUE, DOT_SET, -1), status);
  1596         // Null pointer check.
  1597         if (tempus == NULL) {
  1598             status = U_MEMORY_ALLOCATION_ERROR;
  1599             return (UChar)0x0000;
  1601         dotStandIn = generateStandInFor(tempus, status);
  1603     return dotStandIn;
  1606 /**
  1607  * Append the value of the given variable name to the given
  1608  * UnicodeString.
  1609  */
  1610 void TransliteratorParser::appendVariableDef(const UnicodeString& name,
  1611                                                   UnicodeString& buf,
  1612                                                   UErrorCode& status) {
  1613     const UnicodeString* s = (const UnicodeString*) variableNames.get(name);
  1614     if (s == NULL) {
  1615         // We allow one undefined variable so that variable definition
  1616         // statements work.  For the first undefined variable we return
  1617         // the special placeholder variableLimit-1, and save the variable
  1618         // name.
  1619         if (undefinedVariableName.length() == 0) {
  1620             undefinedVariableName = name;
  1621             if (variableNext >= variableLimit) {
  1622                 // throw new RuntimeException("Private use variables exhausted");
  1623                 status = U_ILLEGAL_ARGUMENT_ERROR;
  1624                 return;
  1626             buf.append((UChar) --variableLimit);
  1627         } else {
  1628             //throw new IllegalArgumentException("Undefined variable $"
  1629             //                                   + name);
  1630             status = U_ILLEGAL_ARGUMENT_ERROR;
  1631             return;
  1633     } else {
  1634         buf.append(*s);
  1638 /**
  1639  * Glue method to get around access restrictions in C++.
  1640  */
  1641 /*Transliterator* TransliteratorParser::createBasicInstance(const UnicodeString& id, const UnicodeString* canonID) {
  1642     return Transliterator::createBasicInstance(id, canonID);
  1643 }*/
  1645 U_NAMESPACE_END
  1647 U_CAPI int32_t
  1648 utrans_stripRules(const UChar *source, int32_t sourceLen, UChar *target, UErrorCode *status) {
  1649     U_NAMESPACE_USE
  1651     //const UChar *sourceStart = source;
  1652     const UChar *targetStart = target;
  1653     const UChar *sourceLimit = source+sourceLen;
  1654     UChar *targetLimit = target+sourceLen;
  1655     UChar32 c = 0;
  1656     UBool quoted = FALSE;
  1657     int32_t index;
  1659     uprv_memset(target, 0, sourceLen*U_SIZEOF_UCHAR);
  1661     /* read the rules into the buffer */
  1662     while (source < sourceLimit)
  1664         index=0;
  1665         U16_NEXT_UNSAFE(source, index, c);
  1666         source+=index;
  1667         if(c == QUOTE) {
  1668             quoted = (UBool)!quoted;
  1670         else if (!quoted) {
  1671             if (c == RULE_COMMENT_CHAR) {
  1672                 /* skip comments and all preceding spaces */
  1673                 while (targetStart < target && *(target - 1) == 0x0020) {
  1674                     target--;
  1676                 do {
  1677                     c = *(source++);
  1679                 while (c != CR && c != LF);
  1681             else if (c == ESCAPE) {
  1682                 UChar32   c2 = *source;
  1683                 if (c2 == CR || c2 == LF) {
  1684                     /* A backslash at the end of a line. */
  1685                     /* Since we're stripping lines, ignore the backslash. */
  1686                     source++;
  1687                     continue;
  1689                 if (c2 == 0x0075 && source+5 < sourceLimit) { /* \u seen. \U isn't unescaped. */
  1690                     int32_t escapeOffset = 0;
  1691                     UnicodeString escapedStr(source, 5);
  1692                     c2 = escapedStr.unescapeAt(escapeOffset);
  1694                     if (c2 == (UChar32)0xFFFFFFFF || escapeOffset == 0)
  1696                         *status = U_PARSE_ERROR;
  1697                         return 0;
  1699                     if (!PatternProps::isWhiteSpace(c2) && !u_iscntrl(c2) && !u_ispunct(c2)) {
  1700                         /* It was escaped for a reason. Write what it was suppose to be. */
  1701                         source+=5;
  1702                         c = c2;
  1705                 else if (c2 == QUOTE) {
  1706                     /* \' seen. Make sure we don't do anything when we see it again. */
  1707                     quoted = (UBool)!quoted;
  1711         if (c == CR || c == LF)
  1713             /* ignore spaces carriage returns, and all leading spaces on the next line.
  1714             * and line feed unless in the form \uXXXX
  1715             */
  1716             quoted = FALSE;
  1717             while (source < sourceLimit) {
  1718                 c = *(source);
  1719                 if (c != CR && c != LF && c != 0x0020) {
  1720                     break;
  1722                 source++;
  1724             continue;
  1727         /* Append UChar * after dissembling if c > 0xffff*/
  1728         index=0;
  1729         U16_APPEND_UNSAFE(target, index, c);
  1730         target+=index;
  1732     if (target < targetLimit) {
  1733         *target = 0;
  1735     return (int32_t)(target-targetStart);
  1738 #endif /* #if !UCONFIG_NO_TRANSLITERATION */

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