1/*
2 **********************************************************************
3 *   Copyright (C) 1999-2015, 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/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"
42
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
48
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) /*#*/
54
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) /*?*/
65
66#define DOT                ((UChar)46)     /*.*/
67
68static const UChar DOT_SET[] = { // "[^[:Zp:][:Zl:]\r\n$]";
69    91, 94, 91, 58, 90, 112, 58, 93, 91, 58, 90,
70    108, 58, 93, 92, 114, 92, 110, 36, 93, 0
71};
72
73// A function is denoted &Source-Target/Variant(text)
74#define FUNCTION           ((UChar)38)     /*&*/
75
76// Aliases for some of the syntax characters. These are provided so
77// transliteration rules can be expressed in XML without clashing with
78// XML syntax characters '<', '>', and '&'.
79#define ALT_REVERSE_RULE_OP ((UChar)0x2190) // Left Arrow
80#define ALT_FORWARD_RULE_OP ((UChar)0x2192) // Right Arrow
81#define ALT_FWDREV_RULE_OP  ((UChar)0x2194) // Left Right Arrow
82#define ALT_FUNCTION        ((UChar)0x2206) // Increment (~Greek Capital Delta)
83
84// Special characters disallowed at the top level
85static const UChar ILLEGAL_TOP[] = {41,0}; // ")"
86
87// Special characters disallowed within a segment
88static const UChar ILLEGAL_SEG[] = {123,125,124,64,0}; // "{}|@"
89
90// Special characters disallowed within a function argument
91static const UChar ILLEGAL_FUNC[] = {94,40,46,42,43,63,123,125,124,64,0}; // "^(.*+?{}|@"
92
93// By definition, the ANCHOR_END special character is a
94// trailing SymbolTable.SYMBOL_REF character.
95// private static final char ANCHOR_END       = '$';
96
97static 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};
102
103static 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};
109
110// These are also used in Transliterator::toRules()
111static const int32_t ID_TOKEN_LEN = 2;
112static const UChar   ID_TOKEN[]   = { 0x3A, 0x3A }; // ':', ':'
113
114/*
115commented out until we do real ::BEGIN/::END functionality
116static const int32_t BEGIN_TOKEN_LEN = 5;
117static const UChar BEGIN_TOKEN[] = { 0x42, 0x45, 0x47, 0x49, 0x4e }; // 'BEGIN'
118
119static const int32_t END_TOKEN_LEN = 3;
120static const UChar END_TOKEN[] = { 0x45, 0x4e, 0x44 }; // 'END'
121*/
122
123U_NAMESPACE_BEGIN
124
125//----------------------------------------------------------------------
126// BEGIN ParseData
127//----------------------------------------------------------------------
128
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 */
135class ParseData : public UMemory, public SymbolTable {
136public:
137    const TransliterationRuleData* data; // alias
138
139    const UVector* variablesVector; // alias
140
141    const Hashtable* variableNames; // alias
142
143    ParseData(const TransliterationRuleData* data = 0,
144              const UVector* variablesVector = 0,
145              const Hashtable* variableNames = 0);
146
147    virtual ~ParseData();
148
149    virtual const UnicodeString* lookup(const UnicodeString& s) const;
150
151    virtual const UnicodeFunctor* lookupMatcher(UChar32 ch) const;
152
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);
160
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);
166
167private:
168    ParseData(const ParseData &other); // forbid copying of this class
169    ParseData &operator=(const ParseData &other); // forbid copying of this class
170};
171
172ParseData::ParseData(const TransliterationRuleData* d,
173                     const UVector* sets,
174                     const Hashtable* vNames) :
175    data(d), variablesVector(sets), variableNames(vNames) {}
176
177ParseData::~ParseData() {}
178
179/**
180 * Implement SymbolTable API.
181 */
182const UnicodeString* ParseData::lookup(const UnicodeString& name) const {
183    return (const UnicodeString*) variableNames->get(name);
184}
185
186/**
187 * Implement SymbolTable API.
188 */
189const 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}
201
202/**
203 * Implement SymbolTable API.  Parse out a symbol reference
204 * name.
205 */
206UnicodeString 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}
225
226UBool 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}
236
237/**
238 * Return true if the given character is a replacer standin or a plain
239 * character (non standin).
240 */
241UBool 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}
251
252//----------------------------------------------------------------------
253// BEGIN RuleHalf
254//----------------------------------------------------------------------
255
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 */
261class RuleHalf : public UMemory {
262
263public:
264
265    UnicodeString text;
266
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
270
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
281
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;
285
286    UBool anchorStart;
287    UBool anchorEnd;
288
289    /**
290     * The segment number from 1..n of the next '(' we see
291     * during parsing; 1-based.
292     */
293    int32_t nextSegmentNumber;
294
295    TransliteratorParser& parser;
296
297    //--------------------------------------------------
298    // Methods
299
300    RuleHalf(TransliteratorParser& parser);
301    ~RuleHalf();
302
303    int32_t parse(const UnicodeString& rule, int32_t pos, int32_t limit, UErrorCode& status);
304
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);
310
311    /**
312     * Remove context.
313     */
314    void removeContext();
315
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);
321
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);
327
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    }
334
335private:
336    // Disallowed methods; no impl.
337    RuleHalf(const RuleHalf&);
338    RuleHalf& operator=(const RuleHalf&);
339};
340
341RuleHalf::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}
352
353RuleHalf::~RuleHalf() {
354}
355
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 */
362int32_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);
366
367    if (cursorOffset > 0 && cursor != cursorOffsetPos) {
368        return syntaxError(U_MISPLACED_CURSOR_OFFSET, rule, start, status);
369    }
370
371    return pos;
372}
373
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 */
397int32_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();
410
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();
487
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        }
496
497        if (!parser.checkVariableRange(c)) {
498            return syntaxError(U_VARIABLE_RANGE_OVERLAP, rule, start, status);
499        }
500
501        if (illegal.indexOf(c) >= 0) {
502            syntaxError(U_ILLEGAL_CHARACTER, rule, start, status);
503        }
504
505        switch (c) {
506
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();
523
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
528
529                // Parse the segment
530                pos = parseSection(rule, pos, limit, buf, UnicodeString(TRUE, ILLEGAL_SEG, -1), TRUE, status);
531
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                }
542
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                }
560
561                Transliterator *t = single->createInstance();
562                delete single;
563                if (t == NULL) {
564                    return syntaxError(U_INVALID_FUNCTION, rule, start, status);
565                }
566
567                // bufSegStart is the offset in buf to the first
568                // character of the segment we are parsing.
569                int32_t bufSegStart = buf.length();
570
571                // Parse the segment
572                pos = parseSection(rule, iref, limit, buf, UnicodeString(TRUE, ILLEGAL_FUNC, -1), TRUE, status);
573
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                }
583
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                }
653
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                }
671
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;
698
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;
707
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;
751
752
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    }
770
771    return pos;
772}
773
774/**
775 * Remove context.
776 */
777void 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}
789
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 */
794UBool 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}
804
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 */
809UBool 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}
819
820//----------------------------------------------------------------------
821// PUBLIC API
822//----------------------------------------------------------------------
823
824/**
825 * Constructor.
826 */
827TransliteratorParser::TransliteratorParser(UErrorCode &statusReturn) :
828dataVector(statusReturn),
829idBlockVector(statusReturn),
830variablesVector(statusReturn),
831segmentObjects(statusReturn)
832{
833    idBlockVector.setDeleter(uprv_deleteUObject);
834    curData = NULL;
835    compoundFilter = NULL;
836    parseData = NULL;
837    variableNames.setValueDeleter(uprv_deleteUObject);
838}
839
840/**
841 * Destructor.
842 */
843TransliteratorParser::~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}
851
852void
853TransliteratorParser::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}
862
863/**
864 * Return the compound filter parsed by parse().  Caller owns result.
865 */
866UnicodeSet* TransliteratorParser::orphanCompoundFilter() {
867    UnicodeSet* f = compoundFilter;
868    compoundFilter = NULL;
869    return f;
870}
871
872//----------------------------------------------------------------------
873// Private implementation
874//----------------------------------------------------------------------
875
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 */
884void 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;
891
892    UBool parsingIDs = TRUE;
893    int32_t ruleCount = 0;
894
895    while (!dataVector.isEmpty()) {
896        delete (TransliterationRuleData*)(dataVector.orphanElementAt(0));
897    }
898    if (U_FAILURE(status)) {
899        return;
900    }
901
902    idBlockVector.removeAllElements();
903    curData = NULL;
904    direction = theDirection;
905    ruleCount = 0;
906
907    delete compoundFilter;
908    compoundFilter = NULL;
909
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    }
919
920    dotStandIn = (UChar) -1;
921
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();
927
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;
935
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        }
950
951        // skip empty rules
952        if (c == END_OF_RULE)
953            continue;
954
955        // keep track of how many rules we've seen
956        ++ruleCount;
957
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            }
971
972            int32_t p = pos;
973
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            }
984
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.
989
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                }
996
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))
1004                    {
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;
1012                        }
1013                    } else {
1014                        delete f;
1015                    }
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);
1020                }
1021            }
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;
1031                }
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;
1043                }
1044                parseData->data = curData;
1045
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);
1051            }
1052
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);
1057                }
1058                pos = ppp;
1059            // Parse a rule
1060            } else {
1061                pos = parseRule(rule, pos, limit, status);
1062            }
1063        }
1064    }
1065
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;
1072        }
1073        if (direction == UTRANS_FORWARD)
1074            idBlockVector.addElement(tempstr, status);
1075        else
1076            idBlockVector.insertElementAt(tempstr, 0, status);
1077    }
1078    else if (!parsingIDs && curData != NULL) {
1079        if (direction == UTRANS_FORWARD)
1080            dataVector.addElement(curData, status);
1081        else
1082            dataVector.insertElementAt(curData, 0, status);
1083    }
1084
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;
1099                }
1100                data->variablesAreOwned = (i == 0);
1101            }
1102
1103            for (int32_t j = 0; j < data->variablesLength; j++) {
1104                data->variables[j] =
1105                    ((UnicodeSet*)variablesVector.elementAt(j));
1106            }
1107
1108            data->variableNames.removeAll();
1109            int32_t pos = UHASH_FIRST;
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;
1116                }
1117                data->variableNames.put(*((UnicodeString*)(he->key.pointer)),
1118                    tempus, status);
1119                he = variableNames.nextElement(pos);
1120            }
1121        }
1122        variablesVector.removeAllElements();   // keeps them from getting deleted when we succeed
1123
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;
1129            }
1130        }
1131
1132        for (i = 0; i < dataVectorSize; i++) {
1133            TransliterationRuleData* data = (TransliterationRuleData*)dataVector.elementAt(i);
1134            data->ruleSet.freeze(parseError, status);
1135        }
1136        if (idBlockVector.size() == 1 && ((UnicodeString*)idBlockVector.elementAt(0))->isEmpty()) {
1137            idBlockVector.removeElementAt(0);
1138        }
1139    }
1140}
1141
1142/**
1143 * Set the variable range to [start, end] (inclusive).
1144 */
1145void 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;
1149    }
1150
1151    curData->variablesBase = (UChar) start;
1152    if (dataVector.size() == 0) {
1153        variableNext = (UChar) start;
1154        variableLimit = (UChar) (end + 1);
1155    }
1156}
1157
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 */
1163UBool TransliteratorParser::checkVariableRange(UChar32 ch) const {
1164    return !(ch >= curData->variablesBase && ch < variableLimit);
1165}
1166
1167/**
1168 * Set the maximum backup to 'backup', in response to a pragma
1169 * statement.
1170 */
1171void TransliteratorParser::pragmaMaximumBackup(int32_t /*backup*/) {
1172    //TODO Finish
1173}
1174
1175/**
1176 * Begin normalizing all rules using the given mode, in response
1177 * to a pragma statement.
1178 */
1179void TransliteratorParser::pragmaNormalizeRules(UNormalizationMode /*mode*/) {
1180    //TODO Finish
1181}
1182
1183static const UChar PRAGMA_USE[] = {0x75,0x73,0x65,0x20,0}; // "use "
1184
1185static 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 # #~;"
1186
1187static 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 #~;"
1188
1189static const UChar PRAGMA_NFD_RULES[] = {0x7E,0x6E,0x66,0x64,0x20,0x72,0x75,0x6C,0x65,0x73,0x7E,0x3B,0}; // "~nfd rules~;"
1190
1191static const UChar PRAGMA_NFC_RULES[] = {0x7E,0x6E,0x66,0x63,0x20,0x72,0x75,0x6C,0x65,0x73,0x7E,0x3B,0}; // "~nfc rules~;"
1192
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 */
1199UBool 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;
1202}
1203
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 */
1213int32_t TransliteratorParser::parsePragma(const UnicodeString& rule, int32_t pos, int32_t limit, UErrorCode& status) {
1214    int32_t array[2];
1215
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;
1220
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;
1230    }
1231
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;
1236    }
1237
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;
1242    }
1243
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;
1248    }
1249
1250    // Syntax error: unable to parse pragma
1251    return -1;
1252}
1253
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.
1258 *
1259 * Important:  The character at pos must be a non-whitespace character
1260 * that is not the comment character.
1261 *
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 */
1267int32_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;
1272
1273    // Set up segments data
1274    segmentStandins.truncate(0);
1275    segmentObjects.removeAllElements();
1276
1277    // Use pointers to automatics to make swapping possible.
1278    RuleHalf _left(*this), _right(*this);
1279    RuleHalf* left = &_left;
1280    RuleHalf* right = &_right;
1281
1282    undefinedVariableName.remove();
1283    pos = left->parse(rule, pos, limit, status);
1284    if (U_FAILURE(status)) {
1285        return start;
1286    }
1287
1288    if (pos == limit || u_strchr(gOPERATORS, (op = rule.charAt(--pos))) == NULL) {
1289        return syntaxError(U_MISSING_OPERATOR, rule, start, status);
1290    }
1291    ++pos;
1292
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;
1298    }
1299
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;
1311    }
1312
1313    pos = right->parse(rule, pos, limit, status);
1314    if (U_FAILURE(status)) {
1315        return start;
1316    }
1317
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);
1324        }
1325    }
1326
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.
1332
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);
1338        }
1339        if (left->text.length() != 1 || left->text.charAt(0) != variableLimit) {
1340            // "Malformed LHS"
1341            return syntaxError(U_MALFORMED_VARIABLE_DEFINITION, rule, start, status);
1342        }
1343        if (left->anchorStart || left->anchorEnd ||
1344            right->anchorStart || right->anchorEnd) {
1345            return syntaxError(U_MALFORMED_VARIABLE_DEFINITION, rule, start, status);
1346        }
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);
1352        }
1353        variableNames.put(undefinedVariableName, value, status);
1354        ++variableLimit;
1355        return pos;
1356    }
1357
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);
1364    }
1365
1366    // Verify segments
1367    if (segmentStandins.length() > segmentObjects.size()) {
1368        syntaxError(U_UNDEFINED_SEGMENT_REFERENCE, rule, start, status);
1369    }
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
1373        }
1374    }
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
1378        }
1379    }
1380
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;
1386    }
1387
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;
1393    }
1394
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;
1402    }
1403
1404    // Normalize context
1405    if (left->ante < 0) {
1406        left->ante = 0;
1407    }
1408    if (left->post < 0) {
1409        left->post = left->text.length();
1410    }
1411
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) {
1429
1430        return syntaxError(U_MALFORMED_RULE, rule, start, status);
1431    }
1432
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);
1440        }
1441        segmentObjects.toArray((void**) segmentsArray);
1442    }
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);
1455    }
1456
1457    curData->ruleSet.addRule(temptr, status);
1458
1459    return pos;
1460}
1461
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 */
1471int32_t TransliteratorParser::syntaxError(UErrorCode parseErrorCode,
1472                                          const UnicodeString& rule,
1473                                          int32_t pos,
1474                                          UErrorCode& status)
1475{
1476    parseError.offset = pos;
1477    parseError.line = 0 ; /* we are not using line numbers */
1478
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;
1483
1484    rule.extract(start,stop-start,parseError.preContext);
1485    //null terminate the buffer
1486    parseError.preContext[stop-start] = 0;
1487
1488    //for post-context
1489    start = pos;
1490    stop  = uprv_min(pos + LEN, rule.length());
1491
1492    rule.extract(start,stop-start,parseError.postContext);
1493    //null terminate the buffer
1494    parseError.postContext[stop-start]= 0;
1495
1496    status = (UErrorCode)parseErrorCode;
1497    return pos;
1498
1499}
1500
1501/**
1502 * Parse a UnicodeSet out, store it, and return the stand-in character
1503 * used to represent it.
1504 */
1505UChar 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.
1513    }
1514    set->compact();
1515    return generateStandInFor(set, status);
1516}
1517
1518/**
1519 * Generate and return a stand-in for a new UnicodeFunctor.  Store
1520 * the matcher (adopt it).
1521 */
1522UChar TransliteratorParser::generateStandInFor(UnicodeFunctor* adopted, UErrorCode& status) {
1523    // assert(obj != null);
1524
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);
1530        }
1531    }
1532
1533    if (variableNext >= variableLimit) {
1534        delete adopted;
1535        status = U_VARIABLE_RANGE_EXHAUSTED;
1536        return 0;
1537    }
1538    variablesVector.addElement(adopted, status);
1539    return variableNext++;
1540}
1541
1542/**
1543 * Return the standin for segment seg (1-based).
1544 */
1545UChar 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);
1550    }
1551    UChar c = segmentStandins.charAt(seg-1);
1552    if (c == empty) {
1553        if (variableNext >= variableLimit) {
1554            status = U_VARIABLE_RANGE_EXHAUSTED;
1555            return 0;
1556        }
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);
1563    }
1564    return c;
1565}
1566
1567/**
1568 * Set the object for segment seg (1-based).
1569 */
1570void 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);
1577    }
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;
1584    }
1585    segmentObjects.setElementAt(adopted, seg-1);
1586    variablesVector.setElementAt(adopted, index);
1587}
1588
1589/**
1590 * Return the stand-in for the dot set.  It is allocated the first
1591 * time and reused thereafter.
1592 */
1593UChar 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;
1600        }
1601        dotStandIn = generateStandInFor(tempus, status);
1602    }
1603    return dotStandIn;
1604}
1605
1606/**
1607 * Append the value of the given variable name to the given
1608 * UnicodeString.
1609 */
1610void 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;
1625            }
1626            buf.append((UChar) --variableLimit);
1627        } else {
1628            //throw new IllegalArgumentException("Undefined variable $"
1629            //                                   + name);
1630            status = U_ILLEGAL_ARGUMENT_ERROR;
1631            return;
1632        }
1633    } else {
1634        buf.append(*s);
1635    }
1636}
1637
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}*/
1644
1645U_NAMESPACE_END
1646
1647U_CAPI int32_t
1648utrans_stripRules(const UChar *source, int32_t sourceLen, UChar *target, UErrorCode *status) {
1649    U_NAMESPACE_USE
1650
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;
1658
1659    uprv_memset(target, 0, sourceLen*U_SIZEOF_UCHAR);
1660
1661    /* read the rules into the buffer */
1662    while (source < sourceLimit)
1663    {
1664        index=0;
1665        U16_NEXT_UNSAFE(source, index, c);
1666        source+=index;
1667        if(c == QUOTE) {
1668            quoted = (UBool)!quoted;
1669        }
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--;
1675                }
1676                do {
1677                    if (source == sourceLimit) {
1678                        c = U_SENTINEL;
1679                        break;
1680                    }
1681                    c = *(source++);
1682                }
1683                while (c != CR && c != LF);
1684                if (c < 0) {
1685                    break;
1686                }
1687            }
1688            else if (c == ESCAPE && source < sourceLimit) {
1689                UChar32   c2 = *source;
1690                if (c2 == CR || c2 == LF) {
1691                    /* A backslash at the end of a line. */
1692                    /* Since we're stripping lines, ignore the backslash. */
1693                    source++;
1694                    continue;
1695                }
1696                if (c2 == 0x0075 && source+5 < sourceLimit) { /* \u seen. \U isn't unescaped. */
1697                    int32_t escapeOffset = 0;
1698                    UnicodeString escapedStr(source, 5);
1699                    c2 = escapedStr.unescapeAt(escapeOffset);
1700
1701                    if (c2 == (UChar32)0xFFFFFFFF || escapeOffset == 0)
1702                    {
1703                        *status = U_PARSE_ERROR;
1704                        return 0;
1705                    }
1706                    if (!PatternProps::isWhiteSpace(c2) && !u_iscntrl(c2) && !u_ispunct(c2)) {
1707                        /* It was escaped for a reason. Write what it was suppose to be. */
1708                        source+=5;
1709                        c = c2;
1710                    }
1711                }
1712                else if (c2 == QUOTE) {
1713                    /* \' seen. Make sure we don't do anything when we see it again. */
1714                    quoted = (UBool)!quoted;
1715                }
1716            }
1717        }
1718        if (c == CR || c == LF)
1719        {
1720            /* ignore spaces carriage returns, and all leading spaces on the next line.
1721            * and line feed unless in the form \uXXXX
1722            */
1723            quoted = FALSE;
1724            while (source < sourceLimit) {
1725                c = *(source);
1726                if (c != CR && c != LF && c != 0x0020) {
1727                    break;
1728                }
1729                source++;
1730            }
1731            continue;
1732        }
1733
1734        /* Append UChar * after dissembling if c > 0xffff*/
1735        index=0;
1736        U16_APPEND_UNSAFE(target, index, c);
1737        target+=index;
1738    }
1739    if (target < targetLimit) {
1740        *target = 0;
1741    }
1742    return (int32_t)(target-targetStart);
1743}
1744
1745#endif /* #if !UCONFIG_NO_TRANSLITERATION */
1746