scuffed-code/icu4c/source/i18n/rbt_pars.cpp
2000-07-16 13:42:38 +00:00

834 lines
30 KiB
C++

/*
**********************************************************************
* Copyright (C) 1999, International Business Machines
* Corporation and others. All Rights Reserved.
**********************************************************************
* Date Name Description
* 11/17/99 aliu Creation.
**********************************************************************
*/
#include "rbt_pars.h"
#include "unicode/rbt.h"
#include "rbt_rule.h"
#include "unirange.h"
#include "rbt_data.h"
#include "unicode/uniset.h"
#include "cstring.h"
#include "unicode/parsepos.h"
#include "symtable.h"
#include "unicode/parseerr.h"
#include "hash.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
#define OPERATORS UNICODE_STRING("=><", 3)
// 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 SET_OPEN ((UChar)0x005B) /*[*/
#define SET_CLOSE ((UChar)0x005D) /*]*/
#define CURSOR_POS ((UChar)0x007C) /*|*/
#define CURSOR_OFFSET ((UChar)0x0040) /*@*/
const UnicodeString TransliterationRuleParser::gOPERATORS = OPERATORS;
//----------------------------------------------------------------------
// 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 setVariablesVector,
* _not_ data.setVariables.
*/
class ParseData : public SymbolTable {
public:
const TransliterationRuleData* data; // alias
const UVector* setVariablesVector; // alias
ParseData(const TransliterationRuleData* data = 0,
const UVector* setVariablesVector = 0);
virtual const UnicodeString* lookup(const UnicodeString& s) const;
virtual const UnicodeSet* lookupSet(UChar ch) const;
virtual UnicodeString parseReference(const UnicodeString& text,
ParsePosition& pos, int32_t limit) const;
};
ParseData::ParseData(const TransliterationRuleData* d,
const UVector* sets) :
data(d), setVariablesVector(sets) {}
/**
* Implement SymbolTable API.
*/
const UnicodeString* ParseData::lookup(const UnicodeString& name) const {
return (const UnicodeString*) data->variableNames->get(name);
}
/**
* Implement SymbolTable API.
*/
const UnicodeSet* ParseData::lookupSet(UChar ch) const {
// Note that we cannot use data.lookupSet() because the
// set array has not been constructed yet.
const UnicodeSet* set = NULL;
int32_t i = ch - data->setVariablesBase;
if (i >= 0 && i < setVariablesVector->size()) {
int32_t i = ch - data->setVariablesBase;
set = (i < setVariablesVector->size()) ?
(UnicodeSet*) setVariablesVector->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 && !Unicode::isUnicodeIdentifierStart(c)) ||
!Unicode::isUnicodeIdentifierPart(c)) {
break;
}
++i;
}
if (i == start) { // No valid name chars
return result; // Indicate failure with empty string
//if (start > 0) {
// --start;
//}
//limit = ruleEnd(text, start, limit);
//throw new IllegalArgumentException("Illegal variable reference " +
// text.substring(start, limit));
}
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
// Record the position of the segment substrings and references. A
// given side should have segments or segment references, but not
// both.
UVector* segments; // ref substring start,limits
int32_t maxRef; // index of largest ref (1..9)
// 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.
int32_t cursorOffset; // only nonzero on output side
TransliterationRuleParser& parser;
static const UnicodeString gOperators;
//--------------------------------------------------
// Methods
RuleHalf(TransliterationRuleParser& parser);
~RuleHalf();
/**
* Parse one side of a rule, stopping at either the limit,
* the END_OF_RULE character, or an operator. Return
* the pos of the terminating character (or limit).
*/
int32_t parse(const UnicodeString& rule, int32_t pos, int32_t limit,
TransliterationRuleParser& parser);
/**
* Remove context.
*/
void removeContext();
/**
* Create and return an int[] array of segments.
*/
int32_t* createSegments() const;
int syntaxError(int32_t code,
const UnicodeString& rule,
int32_t start) {
return parser.syntaxError(code, rule, start);
}
};
const UnicodeString RuleHalf::gOperators = OPERATORS;
RuleHalf::RuleHalf(TransliterationRuleParser& p) : parser(p) {
cursor = -1;
ante = -1;
post = -1;
segments = NULL;
maxRef = -1;
cursorOffset = 0;
}
RuleHalf::~RuleHalf() {
delete segments;
}
/**
* Parse one side of a rule, stopping at either the limit,
* the END_OF_RULE character, or an operator. Return
* the pos of the terminating character (or limit).
*/
int32_t RuleHalf::parse(const UnicodeString& rule, int32_t pos, int32_t limit,
TransliterationRuleParser& parser) {
int32_t start = pos;
UnicodeString& buf = text;
ParsePosition pp;
int32_t cursorOffsetPos = 0; // Position of first CURSOR_OFFSET on _right_
UnicodeString scratch;
bool_t done = FALSE;
while (pos < limit && !done) {
UChar c = rule.charAt(pos++);
if (Unicode::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;
}
// Handle escapes
if (c == ESCAPE) {
if (pos == limit) {
return syntaxError(RuleBasedTransliterator::TRAILING_BACKSLASH, rule, start);
}
UChar32 escaped = rule.unescapeAt(pos); // pos is already past '\\'
if (escaped == (UChar32) -1) {
return syntaxError(RuleBasedTransliterator::MALFORMED_UNICODE_ESCAPE, rule, start);
}
buf.append((UChar) 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.
*/
for (;;) {
if (iq < 0) {
return syntaxError(RuleBasedTransliterator::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;
}
}
}
continue;
}
if (gOperators.indexOf(c) >= 0) {
--pos; // Backup to point to operator
break;
}
switch (c) {
case SEGMENT_OPEN:
case SEGMENT_CLOSE:
// Handle segment definitions "(" and ")"
// Parse "(", ")"
if (segments == NULL) {
segments = new UVector();
}
if ((c == SEGMENT_OPEN) !=
(segments->size() % 2 == 0)) {
return syntaxError(RuleBasedTransliterator::MISMATCHED_SEGMENT_DELIMITERS,
rule, start);
}
segments->addElement((void*) buf.length());
break;
case END_OF_RULE:
--pos; // Backup to point to END_OF_RULE
done = TRUE;
break;
case SymbolTable::SYMBOL_REF:
// Handle variable references and segment references "$1" .. "$9"
{
// A variable reference must be followed immediately
// by a Unicode identifier start and zero or more
// Unicode identifier part characters, or by a digit
// 1..9 if it is a segment reference.
if (pos == limit) {
return syntaxError(RuleBasedTransliterator::MALFORMED_SYMBOL_REFERENCE, rule, start);
}
// Parse "$1" "$2" .. "$9"
c = rule.charAt(pos);
int32_t r = Unicode::digit(c, 10);
if (r >= 1 && r <= 9) {
if (r > maxRef) {
maxRef = r;
}
buf.append(parser.data->getSegmentStandin(r));
++pos;
} else {
pp.setIndex(pos);
UnicodeString name = parser.parseData->
parseReference(rule, pp, limit);
if (name.length() == 0) {
return syntaxError(RuleBasedTransliterator::MALFORMED_VARIABLE_REFERENCE,
rule, start);
}
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.
//buf.append(parser.getVariableDef(name));
parser.appendVariableDef(name, buf);
}
}
break;
case CONTEXT_ANTE:
if (ante >= 0) {
return syntaxError(RuleBasedTransliterator::MULTIPLE_ANTE_CONTEXTS, rule, start);
}
ante = buf.length();
break;
case CONTEXT_POST:
if (post >= 0) {
return syntaxError(RuleBasedTransliterator::MULTIPLE_POST_CONTEXTS, rule, start);
}
post = buf.length();
break;
case SET_OPEN:
pp.setIndex(pos-1); // Backup to opening '['
buf.append(parser.parseSet(rule, pp));
if (U_FAILURE(parser.status)) {
return syntaxError(RuleBasedTransliterator::MALFORMED_SET, rule, start);
}
pos = pp.getIndex();
break;
case CURSOR_POS:
if (cursor >= 0) {
return syntaxError(RuleBasedTransliterator::MULTIPLE_CURSORS, rule, start);
}
cursor = buf.length();
break;
case CURSOR_OFFSET:
if (cursorOffset < 0) {
if (buf.length() > 0) {
return syntaxError(RuleBasedTransliterator::MISPLACED_CURSOR_OFFSET, rule, start);
}
--cursorOffset;
} else if (cursorOffset > 0) {
if (buf.length() != cursorOffsetPos || cursor >= 0) {
return syntaxError(RuleBasedTransliterator::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(RuleBasedTransliterator::MISPLACED_CURSOR_OFFSET, rule, start);
}
}
break;
// case SET_CLOSE:
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(RuleBasedTransliterator::UNQUOTED_SPECIAL, rule, start);
}
buf.append(c);
break;
}
}
if (cursorOffset > 0 && cursor != cursorOffsetPos) {
return syntaxError(RuleBasedTransliterator::MISPLACED_CURSOR_OFFSET, rule, start);
}
// text = buf.toString();
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;
}
/**
* Create and return an int32_t[] array of segments.
*/
int32_t* RuleHalf::createSegments() const {
if (segments == NULL) {
return NULL;
}
int32_t len = segments->size();
int32_t* result = new int32_t[len + 1];
for (int32_t i=0; i<len; ++i) {
result[i] = (int32_t) segments->elementAt(i);
}
result[len] = -1; // end marker
return result;
}
//----------------------------------------------------------------------
// END RuleHalf
//----------------------------------------------------------------------
TransliterationRuleData*
TransliterationRuleParser::parse(const UnicodeString& rules,
UTransDirection direction,
UParseError* parseError) {
TransliterationRuleParser parser(rules, direction, parseError);
parser.parseRules();
if (U_FAILURE(parser.status)) {
delete parser.data;
parser.data = 0;
}
return parser.data;
}
/**
* @param rules list of rules, separated by newline characters
* @exception IllegalArgumentException if there is a syntax error in the
* rules
*/
TransliterationRuleParser::TransliterationRuleParser(
const UnicodeString& theRules,
UTransDirection theDirection,
UParseError* theParseError) :
rules(theRules), direction(theDirection), data(0), parseError(theParseError) {
parseData = new ParseData(0, &setVariablesVector);
}
/**
* Destructor.
*/
TransliterationRuleParser::~TransliterationRuleParser() {
delete parseData;
}
/**
* 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 TransliterationRuleParser::parseRules(void) {
status = U_ZERO_ERROR;
delete data;
data = new TransliterationRuleData(status);
if (U_FAILURE(status)) {
return;
}
parseData->data = data;
setVariablesVector.removeAllElements();
if (parseError != 0) {
parseError->code = 0;
}
determineVariableRange();
int32_t pos = 0;
int32_t limit = rules.length();
while (pos < limit && U_SUCCESS(status)) {
UChar c = rules.charAt(pos++);
if (Unicode::isWhitespace(c)) {
// Ignore leading whitespace. Note that this is not
// Unicode spaces, but Java spaces -- a subset,
// representing whitespace likely to be seen in code.
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. c is its first
// character, and pos points past c. Lexically parse the
// rule into component pieces.
pos = parseRule(--pos, limit);
}
// Convert the set vector to an array
data->setVariablesLength = setVariablesVector.size();
data->setVariables = data->setVariablesLength == 0 ? 0 : new UnicodeSet*[data->setVariablesLength];
// 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.
for (int32_t i=data->setVariablesLength; i>0; ) {
--i;
data->setVariables[i] =
(UnicodeSet*) setVariablesVector.orphanElementAt(i);
}
// Index the rules
if (U_SUCCESS(status)) {
data->ruleSet.freeze(*data, status);
}
}
/**
* 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 TransliterationRuleParser::parseRule(int32_t pos, int32_t limit) {
// Locate the left side, operator, and right side
int32_t start = pos;
UChar op = 0;
const UnicodeString& rule = rules; // TEMPORARY: FIX LATER
// 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, *this);
if (U_FAILURE(status)) {
return start;
}
if (pos == limit ||
gOPERATORS.indexOf(op = rule.charAt(pos++)) < 0) {
return syntaxError(RuleBasedTransliterator::MISSING_OPERATOR, rule, start);
}
// 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, *this);
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(RuleBasedTransliterator::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(RuleBasedTransliterator::BAD_VARIABLE_DEFINITION, rule, start);
}
if (left->text.length() != 1 || left->text.charAt(0) != variableLimit) {
// "Malformed LHS"
return syntaxError(RuleBasedTransliterator::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) {
syntaxError(// "Undefined variable $" + undefinedVariableName,
RuleBasedTransliterator::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();
delete right->segments;
right->segments = NULL;
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.
if (right->ante >= 0 || right->post >= 0 || left->cursor >= 0 ||
right->segments != NULL || left->maxRef >= 0 ||
(right->cursorOffset != 0 && right->cursor < 0) ||
(right->cursorOffset > (left->text.length() - left->post)) ||
(-right->cursorOffset > left->ante)) {
return syntaxError(RuleBasedTransliterator::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 (left->segments != NULL) {
int n = left->segments->size();
if (n % 2 != 0) {
return syntaxError(RuleBasedTransliterator::MISSING_SEGMENT_CLOSE, rule, start);
}
n /= 2;
if (right->maxRef > n) {
return syntaxError(RuleBasedTransliterator::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), status);
return pos;
}
/**
* 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 TransliterationRuleParser::syntaxError(int32_t parseErrorCode,
const UnicodeString& rule,
int32_t start) {
if (parseError != 0) {
parseError->code = parseErrorCode;
parseError->line = 0; // We don't return a line #
parseError->offset = start; // Character offset from rule start
int32_t end = quotedIndexOf(rule, start, rule.length(), END_OF_RULE);
if (end < 0) {
end = rule.length();
}
int32_t len = uprv_max(end - start, U_PARSE_CONTEXT_LEN-1);
// Extract everything into the preContext and leave the postContext
// blank, since we don't have precise error position.
// TODO: Fix this.
rule.extract(start, len, parseError->preContext); // Current rule
parseError->preContext[len] = 0;
parseError->postContext[0] = 0;
}
status = U_ILLEGAL_ARGUMENT_ERROR;
return start;
}
/**
* Parse a UnicodeSet out, store it, and return the stand-in character
* used to represent it.
*/
UChar TransliterationRuleParser::parseSet(const UnicodeString& rule,
ParsePosition& pos) {
UnicodeSet* set = new UnicodeSet(rule, pos, *parseData, status);
if (variableNext >= variableLimit) {
// throw new RuntimeException("Private use variables exhausted");
delete set;
status = U_ILLEGAL_ARGUMENT_ERROR;
return 0;
}
set->compact();
setVariablesVector.addElement(set);
return variableNext++;
}
/**
* Append the value of the given variable name to the given
* UnicodeString.
*/
void TransliterationRuleParser::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);
}
}
/**
* Determines what part of the private use region of Unicode we can use for
* variable stand-ins. The correct way to do this is as follows: Parse each
* rule, and for forward and reverse rules, take the FROM expression, and
* make a hash of all characters used. The TO expression should be ignored.
* When done, everything not in the hash is available for use. In practice,
* this method may employ some other algorithm for improved speed.
*/
void TransliterationRuleParser::determineVariableRange(void) {
UnicodeRange privateUse(0xE000, 0x1900); // Private use area
UnicodeRange* r = privateUse.largestUnusedSubrange(rules);
data->setVariablesBase = variableNext = variableLimit = (UChar) 0;
if (r != 0) {
// Allocate 9 characters for segment references 1 through 9
data->segmentBase = r->start;
data->setVariablesBase = variableNext = (UChar) (data->segmentBase + 9);
variableLimit = (UChar) (r->start + r->length);
delete r;
}
if (variableNext >= variableLimit) {
status = U_ILLEGAL_ARGUMENT_ERROR;
}
}
/**
* Returns the index of a character, ignoring quoted text.
* For example, in the string "abc'hide'h", the 'h' in "hide" will not be
* found by a search for 'h'.
*/
int32_t TransliterationRuleParser::quotedIndexOf(const UnicodeString& text,
int32_t start, int32_t limit,
UChar charToFind) {
for (int32_t i=start; i<limit; ++i) {
UChar c = text.charAt(i);
if (c == ESCAPE) {
++i;
} else if (c == QUOTE) {
while (++i < limit
&& text.charAt(i) != QUOTE) {}
} else if (c == charToFind) {
return i;
}
}
return -1;
}