/* ********************************************************************** * Copyright (C) 1999-2001, International Business Machines * Corporation and others. All Rights Reserved. ********************************************************************** * Date Name Description * 11/17/99 aliu Creation. ********************************************************************** */ #include "cstring.h" #include "hash.h" #include "quant.h" #include "rbt_data.h" #include "rbt_pars.h" #include "rbt_rule.h" #include "strmatch.h" #include "symtable.h" #include "uvector.h" #include "unicode/parseerr.h" #include "unicode/parsepos.h" #include "unicode/putil.h" #include "unicode/rbt.h" #include "unicode/uchar.h" #include "unicode/ustring.h" #include "unicode/uniset.h" #include "util.h" // Operators #define VARIABLE_DEF_OP ((UChar)0x003D) /*=*/ #define FORWARD_RULE_OP ((UChar)0x003E) /*>*/ #define REVERSE_RULE_OP ((UChar)0x003C) /*<*/ #define FWDREV_RULE_OP ((UChar)0x007E) /*~*/ // internal rep of <> op // Other special characters #define QUOTE ((UChar)0x0027) /*'*/ #define ESCAPE ((UChar)0x005C) /*\*/ #define END_OF_RULE ((UChar)0x003B) /*;*/ #define RULE_COMMENT_CHAR ((UChar)0x0023) /*#*/ #define SEGMENT_OPEN ((UChar)0x0028) /*(*/ #define SEGMENT_CLOSE ((UChar)0x0029) /*)*/ #define CONTEXT_ANTE ((UChar)0x007B) /*{*/ #define CONTEXT_POST ((UChar)0x007D) /*}*/ #define CURSOR_POS ((UChar)0x007C) /*|*/ #define CURSOR_OFFSET ((UChar)0x0040) /*@*/ #define ANCHOR_START ((UChar)0x005E) /*^*/ #define KLEENE_STAR ((UChar)0x002A) /***/ #define ONE_OR_MORE ((UChar)0x002B) /*+*/ #define ZERO_OR_ONE ((UChar)0x003F) /*?*/ #define DOT ((UChar)46) /*.*/ static const UChar DOT_SET[] = { // "[^[:Zp:][:Zl:]\r\n$]"; 91, 94, 91, 58, 90, 112, 58, 93, 91, 58, 90, 108, 58, 93, 92, 114, 92, 110, 36, 93, 0 }; // By definition, the ANCHOR_END special character is a // trailing SymbolTable.SYMBOL_REF character. // private static final char ANCHOR_END = '$'; static const UChar gOPERATORS[] = { 0x3D, 0x3E, 0x3C, 0 // "=><" }; static const UChar HALF_ENDERS[] = { 0x3D, 0x3E, 0x3C, 59, 0 // "=><;" }; // These are also used in Transliterator::toRules() static const int32_t ID_TOKEN_LEN = 2; static const UChar ID_TOKEN[] = { 0x3A, 0x3A }; // ':', ':' U_NAMESPACE_BEGIN //---------------------------------------------------------------------- // BEGIN ParseData //---------------------------------------------------------------------- /** * This class implements the SymbolTable interface. It is used * during parsing to give UnicodeSet access to variables that * have been defined so far. Note that it uses variablesVector, * _not_ data.setVariables. */ class ParseData : public SymbolTable { public: const TransliterationRuleData* data; // alias const UVector* variablesVector; // alias ParseData(const TransliterationRuleData* data = 0, const UVector* variablesVector = 0); virtual const UnicodeString* lookup(const UnicodeString& s) const; virtual const UnicodeMatcher* lookupMatcher(UChar32 ch) const; virtual UnicodeString parseReference(const UnicodeString& text, ParsePosition& pos, int32_t limit) const; }; ParseData::ParseData(const TransliterationRuleData* d, const UVector* sets) : data(d), variablesVector(sets) {} /** * Implement SymbolTable API. */ const UnicodeString* ParseData::lookup(const UnicodeString& name) const { return (const UnicodeString*) data->variableNames->get(name); } /** * Implement SymbolTable API. */ const UnicodeMatcher* ParseData::lookupMatcher(UChar32 ch) const { // Note that we cannot use data.lookupSet() because the // set array has not been constructed yet. const UnicodeMatcher* set = NULL; int32_t i = ch - data->variablesBase; if (i >= 0 && i < variablesVector->size()) { int32_t i = ch - data->variablesBase; set = (i < variablesVector->size()) ? (UnicodeMatcher*) variablesVector->elementAt(i) : 0; } return set; } /** * Implement SymbolTable API. Parse out a symbol reference * name. */ UnicodeString ParseData::parseReference(const UnicodeString& text, ParsePosition& pos, int32_t limit) const { int32_t start = pos.getIndex(); int32_t i = start; UnicodeString result; while (i < limit) { UChar c = text.charAt(i); if ((i==start && !u_isIDStart(c)) || !u_isIDPart(c)) { break; } ++i; } if (i == start) { // No valid name chars return result; // Indicate failure with empty string } pos.setIndex(i); text.extractBetween(start, i, result); return result; } //---------------------------------------------------------------------- // BEGIN RuleHalf //---------------------------------------------------------------------- /** * A class representing one side of a rule. This class knows how to * parse half of a rule. It is tightly coupled to the method * RuleBasedTransliterator.Parser.parseRule(). */ class RuleHalf { public: UnicodeString text; int32_t cursor; // position of cursor in text int32_t ante; // position of ante context marker '{' in text int32_t post; // position of post context marker '}' in text int32_t maxRef; // n where maximum segment ref is $n; 1-based // Record the offset to the cursor either to the left or to the // right of the key. This is indicated by characters on the output // side that allow the cursor to be positioned arbitrarily within // the matching text. For example, abc{def} > | @@@ xyz; changes // def to xyz and moves the cursor to before abc. Offset characters // must be at the start or end, and they cannot move the cursor past // the ante- or postcontext text. Placeholders are only valid in // output text. The length of the ante and post context is // determined at runtime, because of supplementals and quantifiers. int32_t cursorOffset; // only nonzero on output side // Position of first CURSOR_OFFSET on _right_. This will be -1 // for |@, -2 for |@@, etc., and 1 for @|, 2 for @@|, etc. int32_t cursorOffsetPos; UBool anchorStart; UBool anchorEnd; UErrorCode ec; /** * UnicodeMatcher objects corresponding to each segment. */ UVector segments; /** * The segment number from 0..n-1 of the next '(' we see * during parsing; 0-based. */ int32_t nextSegmentNumber; TransliteratorParser& parser; //-------------------------------------------------- // Methods RuleHalf(TransliteratorParser& parser); ~RuleHalf(); int32_t parse(const UnicodeString& rule, int32_t pos, int32_t limit); int32_t parseSection(const UnicodeString& rule, int32_t pos, int32_t limit, UnicodeString& buf, UBool isSegment); /** * Remove context. */ void removeContext(); /** * Create and return a UnicodeMatcher*[] array of segments, * or NULL if there are no segments. */ UnicodeMatcher** createSegments(UErrorCode& status) const; int syntaxError(UErrorCode code, const UnicodeString& rule, int32_t start) { return parser.syntaxError(code, rule, start); } private: // Disallowed methods; no impl. RuleHalf(const RuleHalf&); RuleHalf& operator=(const RuleHalf&); }; RuleHalf::RuleHalf(TransliteratorParser& p) : ec(U_ZERO_ERROR), segments(ec), parser(p) { cursor = -1; ante = -1; post = -1; maxRef = -1; cursorOffset = 0; cursorOffsetPos = 0; anchorStart = anchorEnd = FALSE; segments.removeAllElements(); nextSegmentNumber = 0; } RuleHalf::~RuleHalf() { } /** * Parse one side of a rule, stopping at either the limit, * the END_OF_RULE character, or an operator. * @return the index after the terminating character, or * if limit was reached, limit */ int32_t RuleHalf::parse(const UnicodeString& rule, int32_t pos, int32_t limit) { int32_t start = pos; text.truncate(0); pos = parseSection(rule, pos, limit, text, FALSE); if (cursorOffset > 0 && cursor != cursorOffsetPos) { return syntaxError(U_MISPLACED_CURSOR_OFFSET, rule, start); } return pos; } /** * Parse a section of one side of a rule, stopping at either * the limit, the END_OF_RULE character, an operator, or a * segment close character. This method parses both a * top-level rule half and a segment within such a rule half. * It calls itself recursively to parse segments and nested * segments. * @param buf buffer into which to accumulate the rule pattern * characters, either literal characters from the rule or * standins for UnicodeMatcher objects including segments. * @param isSegment if true, then we've already seen a '(' and * pos on entry points right after it. Accumulate everything * up to the closing ')', put it in a segment matcher object, * generate a standin for it, and add the standin to buf. As * a side effect, update the segments vector with a reference * to the segment matcher. This works recursively for nested * segments. If isSegment is false, just accumulate * characters into buf. * @return the index after the terminating character, or * if limit was reached, limit */ int32_t RuleHalf::parseSection(const UnicodeString& rule, int32_t pos, int32_t limit, UnicodeString& buf, UBool isSegment) { int32_t start = pos; ParsePosition pp; UnicodeString scratch; UBool done = FALSE; int32_t quoteStart = -1; // Most recent 'single quoted string' int32_t quoteLimit = -1; int32_t varStart = -1; // Most recent $variableReference int32_t varLimit = -1; // If isSegment, then bufSegStart is the offset in buf to // the first character of the segment we are parsing. int32_t bufSegStart = 0; int32_t segmentNumber = 0; if (isSegment) { bufSegStart = buf.length(); segmentNumber = nextSegmentNumber++; } while (pos < limit && !done) { // Since all syntax characters are in the BMP, fetching // 16-bit code units suffices here. UChar c = rule.charAt(pos++); if (u_isWhitespace(c)) { // Ignore whitespace. Note that this is not Unicode // spaces, but Java spaces -- a subset, representing // whitespace likely to be seen in code. continue; } if (u_strchr(HALF_ENDERS, c) != NULL) { if (isSegment) { // Unclosed segment return syntaxError(U_UNCLOSED_SEGMENT, rule, start); } break; } if (anchorEnd) { // Text after a presumed end anchor is a syntax err return syntaxError(U_MALFORMED_VARIABLE_REFERENCE, rule, start); } if (UnicodeSet::resemblesPattern(rule, pos-1)) { pp.setIndex(pos-1); // Backup to opening '[' buf.append(parser.parseSet(rule, pp)); if (U_FAILURE(parser.status)) { return syntaxError(U_MALFORMED_SET, rule, start); } pos = pp.getIndex(); continue; } // Handle escapes if (c == ESCAPE) { if (pos == limit) { return syntaxError(U_TRAILING_BACKSLASH, rule, start); } UChar32 escaped = rule.unescapeAt(pos); // pos is already past '\\' if (escaped == (UChar32) -1) { return syntaxError(U_MALFORMED_UNICODE_ESCAPE, rule, start); } if (!parser.checkVariableRange(escaped)) { return syntaxError(U_VARIABLE_RANGE_OVERLAP, rule, start); } buf.append(escaped); continue; } // Handle quoted matter if (c == QUOTE) { int32_t iq = rule.indexOf(QUOTE, pos); if (iq == pos) { buf.append(c); // Parse [''] outside quotes as ['] ++pos; } else { /* This loop picks up a segment of quoted text of the * form 'aaaa' each time through. If this segment * hasn't really ended ('aaaa''bbbb') then it keeps * looping, each time adding on a new segment. When it * reaches the final quote it breaks. */ quoteStart = buf.length(); for (;;) { if (iq < 0) { return syntaxError(U_UNTERMINATED_QUOTE, rule, start); } scratch.truncate(0); rule.extractBetween(pos, iq, scratch); buf.append(scratch); pos = iq+1; if (pos < limit && rule.charAt(pos) == QUOTE) { // Parse [''] inside quotes as ['] iq = rule.indexOf(QUOTE, pos+1); // Continue looping } else { break; } } quoteLimit = buf.length(); for (iq=quoteStart; iq= 1 && r <= 9) { ++pos; while (pos < limit) { c = rule.charAt(pos); int32_t d = u_charDigitValue(c); if (d < 0) { break; } if (r > 214748364 || (r == 214748364 && d > 7)) { return syntaxError(U_UNDEFINED_SEGMENT_REFERENCE, rule, start); } r = 10*r + d; } if (r > maxRef) { maxRef = r; } buf.append(parser.getSegmentStandin(r)); } else { pp.setIndex(pos); UnicodeString name = parser.parseData-> parseReference(rule, pp, limit); if (name.length() == 0) { // This means the '$' was not followed by a // valid name. Try to interpret it as an // end anchor then. If this also doesn't work // (if we see a following character) then signal // an error. anchorEnd = TRUE; break; } pos = pp.getIndex(); // If this is a variable definition statement, // then the LHS variable will be undefined. In // that case appendVariableDef() will append the // special placeholder char variableLimit-1. varStart = buf.length(); parser.appendVariableDef(name, buf); varLimit = buf.length(); } } break; case DOT: buf.append(parser.getDotStandIn()); break; case KLEENE_STAR: case ONE_OR_MORE: case ZERO_OR_ONE: // Quantifiers. We handle single characters, quoted strings, // variable references, and segments. // a+ matches aaa // 'foo'+ matches foofoofoo // $v+ matches xyxyxy if $v == xy // (seg)+ matches segsegseg { if (isSegment && buf.length() == bufSegStart) { // The */+ immediately follows '(' return syntaxError(U_MISPLACED_QUANTIFIER, rule, start); } int32_t qstart, qlimit; // The */+ follows an isolated character or quote // or variable reference if (buf.length() == quoteLimit) { // The */+ follows a 'quoted string' qstart = quoteStart; qlimit = quoteLimit; } else if (buf.length() == varLimit) { // The */+ follows a $variableReference qstart = varStart; qlimit = varLimit; } else { // The */+ follows a single character, possibly // a segment standin qstart = buf.length() - 1; qlimit = qstart + 1; } UnicodeMatcher *m = new StringMatcher(buf, qstart, qlimit, FALSE, *parser.data); int32_t min = 0; int32_t max = Quantifier::MAX; switch (c) { case ONE_OR_MORE: min = 1; break; case ZERO_OR_ONE: min = 0; max = 1; break; // case KLEENE_STAR: // do nothing -- min, max already set } m = new Quantifier(m, min, max); buf.truncate(qstart); buf.append(parser.generateStandInFor(m)); } break; //------------------------------------------------------ // Elements allowed ONLY WITHIN segments //------------------------------------------------------ case SEGMENT_CLOSE: if (isSegment) { // We're done parsing a segment. The relevant // characters are in buf, starting at offset // bufSegStart. Extract them into a string // matcher, and replace them with a standin // for that matcher. StringMatcher *m = new StringMatcher(buf, bufSegStart, buf.length(), TRUE, *parser.data); // Since we call parseSection() recursively, // nested segments will result in segment i+1 // getting parsed and stored before segment i; // be careful with the vector handling here. if ((segmentNumber+1) > segments.size()) { segments.setSize(segmentNumber+1); } segments.setElementAt(m, segmentNumber); buf.truncate(bufSegStart); buf.append(parser.generateStandInFor(m)); done = TRUE; break; } // If we aren't in a segment, then a segment close // character is a syntax error. return syntaxError(U_UNQUOTED_SPECIAL, rule, start); //------------------------------------------------------ // Elements allowed ONLY OUTSIDE segments //------------------------------------------------------ case CONTEXT_ANTE: if (isSegment) { return syntaxError(U_ILLEGAL_CHAR_IN_SEGMENT, rule, start); } if (ante >= 0) { return syntaxError(U_MULTIPLE_ANTE_CONTEXTS, rule, start); } ante = buf.length(); break; case CONTEXT_POST: if (isSegment) { return syntaxError(U_ILLEGAL_CHAR_IN_SEGMENT, rule, start); } if (post >= 0) { return syntaxError(U_MULTIPLE_POST_CONTEXTS, rule, start); } post = buf.length(); break; case CURSOR_POS: if (isSegment) { return syntaxError(U_ILLEGAL_CHAR_IN_SEGMENT, rule, start); } if (cursor >= 0) { return syntaxError(U_MULTIPLE_CURSORS, rule, start); } cursor = buf.length(); break; case CURSOR_OFFSET: if (isSegment) { return syntaxError(U_ILLEGAL_CHAR_IN_SEGMENT, rule, start); } if (cursorOffset < 0) { if (buf.length() > 0) { return syntaxError(U_MISPLACED_CURSOR_OFFSET, rule, start); } --cursorOffset; } else if (cursorOffset > 0) { if (buf.length() != cursorOffsetPos || cursor >= 0) { return syntaxError(U_MISPLACED_CURSOR_OFFSET, rule, start); } ++cursorOffset; } else { if (cursor == 0 && buf.length() == 0) { cursorOffset = -1; } else if (cursor < 0) { cursorOffsetPos = buf.length(); cursorOffset = 1; } else { return syntaxError(U_MISPLACED_CURSOR_OFFSET, rule, start); } } break; //------------------------------------------------------ // Non-special characters //------------------------------------------------------ default: // Disallow unquoted characters other than [0-9A-Za-z] // in the printable ASCII range. These characters are // reserved for possible future use. if (c >= 0x0021 && c <= 0x007E && !((c >= 0x0030/*'0'*/ && c <= 0x0039/*'9'*/) || (c >= 0x0041/*'A'*/ && c <= 0x005A/*'Z'*/) || (c >= 0x0061/*'a'*/ && c <= 0x007A/*'z'*/))) { return syntaxError(U_UNQUOTED_SPECIAL, rule, start); } buf.append(c); break; } } return pos; } /** * Remove context. */ void RuleHalf::removeContext() { //text = text.substring(ante < 0 ? 0 : ante, // post < 0 ? text.length() : post); if (post >= 0) { text.remove(post); } if (ante >= 0) { text.removeBetween(0, ante); } ante = post = -1; anchorStart = anchorEnd = FALSE; } /** * Create and return a UnicodeMatcher*[] array of segments, * or NULL if there are no segments. */ UnicodeMatcher** RuleHalf::createSegments(UErrorCode& status) const { if (segments.size() == 0) { return NULL; } UnicodeMatcher** result = new UnicodeMatcher*[segments.size()]; if (result == NULL) { status = U_MEMORY_ALLOCATION_ERROR; } return (UnicodeMatcher**) segments.toArray((void**) result); } //---------------------------------------------------------------------- // PUBLIC API //---------------------------------------------------------------------- /** * Constructor. */ TransliteratorParser::TransliteratorParser() { data = NULL; compoundFilter = NULL; parseData = NULL; variablesVector = NULL; } /** * Destructor. */ TransliteratorParser::~TransliteratorParser() { delete data; delete compoundFilter; delete parseData; delete variablesVector; } void TransliteratorParser::parse(const UnicodeString& rules, UTransDirection transDirection, UParseError& pe, UErrorCode& ec) { if (U_SUCCESS(ec)) { parseRules(rules, transDirection); pe = parseError; ec = status; } } /** * Return the compound filter parsed by parse(). Caller owns result. */ UnicodeSet* TransliteratorParser::orphanCompoundFilter() { UnicodeSet* f = compoundFilter; compoundFilter = NULL; return f; } /** * Return the data object parsed by parse(). Caller owns result. */ TransliterationRuleData* TransliteratorParser::orphanData() { TransliterationRuleData* d = data; data = NULL; return d; } //---------------------------------------------------------------------- // Private implementation //---------------------------------------------------------------------- /** * Parse the given string as a sequence of rules, separated by newline * characters ('\n'), and cause this object to implement those rules. Any * previous rules are discarded. Typically this method is called exactly * once, during construction. * @exception IllegalArgumentException if there is a syntax error in the * rules */ void TransliteratorParser::parseRules(const UnicodeString& rules, UTransDirection theDirection) { // Clear error struct parseError.line = parseError.offset = -1; parseError.preContext[0] = parseError.postContext[0] = (UChar)0; status = U_ZERO_ERROR; delete data; data = new TransliterationRuleData(status); if (U_FAILURE(status)) { return; } direction = theDirection; ruleCount = 0; delete compoundFilter; compoundFilter = NULL; if (variablesVector == NULL) { variablesVector = new UVector(status); } else { variablesVector->removeAllElements(); } parseData = new ParseData(0, variablesVector); if (parseData == NULL) { status = U_MEMORY_ALLOCATION_ERROR; return; } parseData->data = data; // By default, rules use part of the private use area // E000..F8FF for variables and other stand-ins. Currently // the range F000..F8FF is typically sufficient. The 'use // variable range' pragma allows rule sets to modify this. setVariableRange(0xF000, 0xF8FF); dotStandIn = (UChar) -1; UnicodeString str; // scratch idBlock.truncate(0); idSplitPoint = -1; int32_t pos = 0; int32_t limit = rules.length(); // The mode marks whether we are in the header ::id block, the // rule block, or the footer ::id block. // mode == 0: start: rule->1, ::id->0 // mode == 1: in rules: rule->1, ::id->2 // mode == 2: in footer rule block: rule->ERROR, ::id->2 int32_t mode = 0; // The compound filter offset is an index into idBlockResult. // If it is 0, then the compound filter occurred at the start, // and it is the offset to the _start_ of the compound filter // pattern. Otherwise it is the offset to the _limit_ of the // compound filter pattern within idBlockResult. compoundFilter = NULL; int32_t compoundFilterOffset = -1; while (pos < limit && U_SUCCESS(status)) { UChar c = rules.charAt(pos++); if (u_isWhitespace(c)) { // Ignore leading whitespace. continue; } // Skip lines starting with the comment character if (c == RULE_COMMENT_CHAR) { pos = rules.indexOf((UChar)0x000A /*\n*/, pos) + 1; if (pos == 0) { break; // No "\n" found; rest of rule is a commnet } continue; // Either fall out or restart with next line } // We've found the start of a rule or ID. c is its first // character, and pos points past c. --pos; // Look for an ID token. Must have at least ID_TOKEN_LEN + 1 // chars left. if ((pos + ID_TOKEN_LEN + 1) <= limit && rules.compare(pos, ID_TOKEN_LEN, ID_TOKEN) == 0) { pos += ID_TOKEN_LEN; c = rules.charAt(pos); while (u_isWhitespace(c) && pos < limit) { ++pos; c = rules.charAt(pos); } int32_t lengthBefore = idBlock.length(); if (mode == 1) { mode = 2; // In the forward direction parseID adds elements at the end. // In the reverse direction parseID adds elements at the start. idSplitPoint = (direction == UTRANS_REVERSE) ? 0 : lengthBefore; } int32_t p = pos; UBool sawDelim; UnicodeSet* cpdFilter = NULL; Transliterator::parseID(rules, idBlock, p, sawDelim, cpdFilter, direction,parseError, FALSE,status); if (p == pos || !sawDelim) { // Invalid ::id delete cpdFilter; syntaxError(U_ILLEGAL_ARGUMENT_ERROR, rules, pos); } else { if (direction == UTRANS_REVERSE && idSplitPoint >= 0) { // In the reverse direction parseID adds elements at the start. idSplitPoint += idBlock.length() - lengthBefore; } if (cpdFilter != NULL) { if (compoundFilter != NULL) { syntaxError(U_MULTIPLE_COMPOUND_FILTERS, rules, pos); } compoundFilter = cpdFilter; compoundFilterOffset = (direction == UTRANS_FORWARD) ? lengthBefore : idBlock.length(); } pos = p; } } else if (resemblesPragma(rules, pos, limit)) { int32_t ppp = parsePragma(rules, pos, limit); if (ppp < 0) { syntaxError(U_MALFORMED_PRAGMA, rules, pos); } pos = ppp; } else { // Parse a rule pos = parseRule(rules, pos, limit); if (U_SUCCESS(status)) { ++ruleCount; if (mode == 2) { // ::id in illegal position (because a rule // occurred after the ::id footer block) syntaxError(U_ILLEGAL_ARGUMENT_ERROR,rules,pos); } }else{ syntaxError(status,rules,pos); } mode = 1; } } // Convert the set vector to an array data->variablesLength = variablesVector->size(); data->variables = data->variablesLength == 0 ? 0 : new UnicodeMatcher*[data->variablesLength]; // orphanElement removes the given element and shifts all other // elements down. For performance (and code clarity) we work from // the end back to index 0. int32_t i; for (i=data->variablesLength; i>0; ) { --i; data->variables[i] = (UnicodeSet*) variablesVector->orphanElementAt(i); } // Index the rules if (U_SUCCESS(status)) { if (compoundFilter != NULL) { if ((direction == UTRANS_FORWARD && compoundFilterOffset != 0) || (direction == UTRANS_REVERSE && compoundFilterOffset != idBlock.length())) { status = U_MISPLACED_COMPOUND_FILTER; } } data->ruleSet.freeze(parseError,status); if (idSplitPoint < 0) { idSplitPoint = idBlock.length(); } if (ruleCount == 0) { delete data; data = NULL; } } } /** * Set the variable range to [start, end] (inclusive). */ void TransliteratorParser::setVariableRange(int32_t start, int32_t end) { if (start > end || start < 0 || end > 0xFFFF) { status = U_MALFORMED_PRAGMA; return; } // Segment references work down; variables work up. We don't // know how many of each we will need. data->segmentBase = (UChar) end; data->segmentCount = 0; data->variablesBase = variableNext = (UChar) start; // first private use variableLimit = (UChar) (end + 1); } /** * Assert that the given character is NOT within the variable range. * If it is, return FALSE. This is neccesary to ensure that the * variable range does not overlap characters used in a rule. */ UBool TransliteratorParser::checkVariableRange(UChar32 ch) const { return !(ch >= data->variablesBase && ch < variableLimit); } /** * Set the maximum backup to 'backup', in response to a pragma * statement. */ void TransliteratorParser::pragmaMaximumBackup(int32_t backup) { //TODO Finish } /** * Begin normalizing all rules using the given mode, in response * to a pragma statement. */ void TransliteratorParser::pragmaNormalizeRules(UNormalizationMode mode) { //TODO Finish } static const UChar PRAGMA_USE[] = {0x75,0x73,0x65,0x20,0}; // "use " 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 # #~;" 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 #~;" static const UChar PRAGMA_NFD_RULES[] = {0x7E,0x6E,0x66,0x64,0x20,0x72,0x75,0x6C,0x65,0x73,0x7E,0x3B,0}; // "~nfd rules~;" static const UChar PRAGMA_NFC_RULES[] = {0x7E,0x6E,0x66,0x63,0x20,0x72,0x75,0x6C,0x65,0x73,0x7E,0x3B,0}; // "~nfc rules~;" /** * Return true if the given rule looks like a pragma. * @param pos offset to the first non-whitespace character * of the rule. * @param limit pointer past the last character of the rule. */ UBool TransliteratorParser::resemblesPragma(const UnicodeString& rule, int32_t pos, int32_t limit) { // Must start with /use\s/i return ICU_Utility::parsePattern(rule, pos, limit, PRAGMA_USE, NULL) >= 0; } /** * Parse a pragma. This method assumes resemblesPragma() has * already returned true. * @param pos offset to the first non-whitespace character * of the rule. * @param limit pointer past the last character of the rule. * @return the position index after the final ';' of the pragma, * or -1 on failure. */ int32_t TransliteratorParser::parsePragma(const UnicodeString& rule, int32_t pos, int32_t limit) { int32_t array[2]; // resemblesPragma() has already returned true, so we // know that pos points to /use\s/i; we can skip 4 characters // immediately pos += 4; // Here are the pragmas we recognize: // use variable range 0xE000 0xEFFF; // use maximum backup 16; // use nfd rules; // use nfc rules; int p = ICU_Utility::parsePattern(rule, pos, limit, PRAGMA_VARIABLE_RANGE, array); if (p >= 0) { setVariableRange(array[0], array[1]); return p; } p = ICU_Utility::parsePattern(rule, pos, limit, PRAGMA_MAXIMUM_BACKUP, array); if (p >= 0) { pragmaMaximumBackup(array[0]); return p; } p = ICU_Utility::parsePattern(rule, pos, limit, PRAGMA_NFD_RULES, NULL); if (p >= 0) { pragmaNormalizeRules(UNORM_NFD); return p; } p = ICU_Utility::parsePattern(rule, pos, limit, PRAGMA_NFC_RULES, NULL); if (p >= 0) { pragmaNormalizeRules(UNORM_NFC); return p; } // Syntax error: unable to parse pragma return -1; } /** * MAIN PARSER. Parse the next rule in the given rule string, starting * at pos. Return the index after the last character parsed. Do not * parse characters at or after limit. * * Important: The character at pos must be a non-whitespace character * that is not the comment character. * * This method handles quoting, escaping, and whitespace removal. It * parses the end-of-rule character. It recognizes context and cursor * indicators. Once it does a lexical breakdown of the rule at pos, it * creates a rule object and adds it to our rule list. */ int32_t TransliteratorParser::parseRule(const UnicodeString& rule, int32_t pos, int32_t limit) { // Locate the left side, operator, and right side int32_t start = pos; UChar op = 0; // Use pointers to automatics to make swapping possible. RuleHalf _left(*this), _right(*this); RuleHalf* left = &_left; RuleHalf* right = &_right; undefinedVariableName.remove(); pos = left->parse(rule, pos, limit); if (U_FAILURE(status)) { return start; } if (pos == limit || u_strchr(gOPERATORS, (op = rule.charAt(--pos))) == NULL) { return syntaxError(U_MISSING_OPERATOR, rule, start); } ++pos; // Found an operator char. Check for forward-reverse operator. if (op == REVERSE_RULE_OP && (pos < limit && rule.charAt(pos) == FORWARD_RULE_OP)) { ++pos; op = FWDREV_RULE_OP; } pos = right->parse(rule, pos, limit); if (U_FAILURE(status)) { return start; } if (pos < limit) { if (rule.charAt(--pos) == END_OF_RULE) { ++pos; } else { // RuleHalf parser must have terminated at an operator return syntaxError(U_UNQUOTED_SPECIAL, rule, start); } } if (op == VARIABLE_DEF_OP) { // LHS is the name. RHS is a single character, either a literal // or a set (already parsed). If RHS is longer than one // character, it is either a multi-character string, or multiple // sets, or a mixture of chars and sets -- syntax error. // We expect to see a single undefined variable (the one being // defined). if (undefinedVariableName.length() == 0) { // "Missing '$' or duplicate definition" return syntaxError(U_BAD_VARIABLE_DEFINITION, rule, start); } if (left->text.length() != 1 || left->text.charAt(0) != variableLimit) { // "Malformed LHS" return syntaxError(U_MALFORMED_VARIABLE_DEFINITION, rule, start); } if (left->anchorStart || left->anchorEnd || right->anchorStart || right->anchorEnd) { return syntaxError(U_MALFORMED_VARIABLE_DEFINITION, rule, start); } // We allow anything on the right, including an empty string. UnicodeString* value = new UnicodeString(right->text); data->variableNames->put(undefinedVariableName, value, status); ++variableLimit; return pos; } // If this is not a variable definition rule, we shouldn't have // any undefined variable names. if (undefinedVariableName.length() != 0) { return syntaxError(// "Undefined variable $" + undefinedVariableName, U_UNDEFINED_VARIABLE, rule, start); } // If the direction we want doesn't match the rule // direction, do nothing. if (op != FWDREV_RULE_OP && ((direction == UTRANS_FORWARD) != (op == FORWARD_RULE_OP))) { return pos; } // Transform the rule into a forward rule by swapping the // sides if necessary. if (direction == UTRANS_REVERSE) { left = &_right; right = &_left; } // Remove non-applicable elements in forward-reverse // rules. Bidirectional rules ignore elements that do not // apply. if (op == FWDREV_RULE_OP) { right->removeContext(); right->segments.removeAllElements(); left->cursor = left->maxRef = -1; left->cursorOffset = 0; } // Normalize context if (left->ante < 0) { left->ante = 0; } if (left->post < 0) { left->post = left->text.length(); } // Context is only allowed on the input side. Cursors are only // allowed on the output side. Segment delimiters can only appear // on the left, and references on the right. Cursor offset // cannot appear without an explicit cursor. Cursor offset // cannot place the cursor outside the limits of the context. // Anchors are only allowed on the input side. if (right->ante >= 0 || right->post >= 0 || left->cursor >= 0 || right->segments.size() > 0 || left->maxRef >= 0 || (right->cursorOffset != 0 && right->cursor < 0) || // - The following two checks were used to ensure that the // - the cursor offset stayed within the ante- or postcontext. // - However, with the addition of quantifiers, we have to // - allow arbitrary cursor offsets and do runtime checking. //(right->cursorOffset > (left->text.length() - left->post)) || //(-right->cursorOffset > left->ante) || right->anchorStart || right->anchorEnd || !isValidOutput(right->text) || left->ante > left->post) { return syntaxError(U_MALFORMED_RULE, rule, start); } // Check integrity of segments and segment references. Each // segment's start must have a corresponding limit, and the // references must not refer to segments that do not exist. if (right->maxRef > left->segments.size()) { return syntaxError(U_UNDEFINED_SEGMENT_REFERENCE, rule, start); } data->ruleSet.addRule(new TransliterationRule( left->text, left->ante, left->post, right->text, right->cursor, right->cursorOffset, left->createSegments(status), left->segments.size(), left->anchorStart, left->anchorEnd, data, status), status); return pos; } /** * Return true if the given string looks like valid output, that is, * does not contain quantifiers or other special input-only elements. */ UBool TransliteratorParser::isValidOutput(const UnicodeString& output) const { for (int32_t i=0; ilookupMatcher(c) != NULL) { return FALSE; } } return TRUE; } /** * Called by main parser upon syntax error. Search the rule string * for the probable end of the rule. Of course, if the error is that * the end of rule marker is missing, then the rule end will not be found. * In any case the rule start will be correctly reported. * @param msg error description * @param rule pattern string * @param start position of first character of current rule */ int32_t TransliteratorParser::syntaxError(UErrorCode parseErrorCode, const UnicodeString& rule, int32_t pos) { parseError.offset = pos; parseError.line = 0 ; /* we are not using line numbers */ // for pre-context const int32_t LEN = U_PARSE_CONTEXT_LEN - 1; int32_t start = uprv_max(pos - LEN, 0); int32_t stop = pos; rule.extract(start,stop-start,parseError.preContext); //null terminate the buffer parseError.preContext[stop-start] = 0; //for post-context start = pos; stop = uprv_min(pos + LEN, rule.length()); rule.extract(start,stop-start,parseError.postContext); //null terminate the buffer parseError.postContext[stop-start]= 0; status = (UErrorCode)parseErrorCode; return pos; } /** * Parse a UnicodeSet out, store it, and return the stand-in character * used to represent it. */ UChar TransliteratorParser::parseSet(const UnicodeString& rule, ParsePosition& pos) { UnicodeSet* set = new UnicodeSet(rule, pos, *parseData, status); set->compact(); return generateStandInFor(set); } /** * Generate and return a stand-in for a new UnicodeMatcher. Store * the matcher (adopt it). */ UChar TransliteratorParser::generateStandInFor(UnicodeMatcher* adopted) { // assert(adopted != 0); if (variableNext >= variableLimit) { // throw new RuntimeException("Private use variables exhausted"); delete adopted; status = U_VARIABLE_RANGE_EXHAUSTED; return 0; } variablesVector->addElement(adopted, status); return variableNext++; } /** * Return the stand-in for the dot set. It is allocated the first * time and reused thereafter. */ UChar TransliteratorParser::getDotStandIn() { if (dotStandIn == (UChar) -1) { dotStandIn = generateStandInFor(new UnicodeSet(DOT_SET, status)); } return dotStandIn; } /** * Append the value of the given variable name to the given * UnicodeString. */ void TransliteratorParser::appendVariableDef(const UnicodeString& name, UnicodeString& buf) { const UnicodeString* s = (const UnicodeString*) data->variableNames->get(name); if (s == NULL) { // We allow one undefined variable so that variable definition // statements work. For the first undefined variable we return // the special placeholder variableLimit-1, and save the variable // name. if (undefinedVariableName.length() == 0) { undefinedVariableName = name; if (variableNext >= variableLimit) { // throw new RuntimeException("Private use variables exhausted"); status = U_ILLEGAL_ARGUMENT_ERROR; return; } buf.append((UChar) --variableLimit); } else { //throw new IllegalArgumentException("Undefined variable $" // + name); status = U_ILLEGAL_ARGUMENT_ERROR; return; } } else { buf.append(*s); } } UChar TransliteratorParser::getSegmentStandin(int32_t r) { // assert(r>=1); if (r > data->segmentCount) { data->segmentCount = r; variableLimit = data->segmentBase - r + 1; if (variableNext >= variableLimit) { status = U_ILLEGAL_ARGUMENT_ERROR; } } return data->getSegmentStandin(r); } U_NAMESPACE_END