// // file: rbbiscan.cpp // // Copyright (C) 2002, International Business Machines Corporation and others. // All Rights Reserved. // // This file contains the Rule Based Break Iterator Rule Builder functions for // scanning the rules and assembling a parse tree. This is the first phase // of compiling the rules. // // The overall of the rules is managed by class RBBIRuleBuilder, which will // create and use an instance of this class as part of the process. // #include "unicode/unistr.h" #include "unicode/uniset.h" #include "unicode/uchar.h" #include "unicode/uchriter.h" #include "unicode/parsepos.h" #include "unicode/parseerr.h" #include "cmemory.h" #include "rbbirpt.h" // Contains state table for the rbbi rules parser. // generated by a Perl script. #include "rbbirb.h" #include "rbbinode.h" #include "rbbiscan.h" #include // TODO - getrid of this, or make conditional on debugging #include #include #include U_NAMESPACE_BEGIN const char RBBIRuleScanner::fgClassID=0; // // Forward Declarations // U_CDECL_BEGIN static void U_EXPORT2 U_CALLCONV RBBISetTable_deleter(void *p); U_CDECL_END //---------------------------------------------------------------------------------------- // // Unicode Set init strings for each of the character classes needed for parsing a rule file. // (Initialized with hex values for portability to EBCDIC based machines. // Really ugly, but there's no good way to avoid it.) // // The sets are referred to by name in the rbbirpt.txt, which is the // source form of the state transition table for the RBBI rule parser. // //---------------------------------------------------------------------------------------- static const UChar gRuleSet_rule_char_pattern[] = { // [ ^ [ \ p { Z } \ u 0 0 2 0 0x5b, 0x5e, 0x5b, 0x5c, 0x70, 0x7b, 0x5a, 0x7d, 0x5c, 0x75, 0x30, 0x30, 0x32, 0x30, // - \ u 0 0 7 f ] - [ \ p 0x2d, 0x5c, 0x75, 0x30, 0x30, 0x37, 0x66, 0x5d, 0x2d, 0x5b, 0x5c, 0x70, // { L } ] - [ \ p { N } ] ] 0x7b, 0x4c, 0x7d, 0x5d, 0x2d, 0x5b, 0x5c, 0x70, 0x7b, 0x4e, 0x7d, 0x5d, 0x5d, 0}; static const UChar gRuleSet_white_space_pattern[] = // [ \ p { Z } \ n \ r \ t ] { 0x5b, 0x5c, 0x70, 0x7b, 0x5a, 0x7d, 0x5c, 0x6e, 0x5c, 0x72, 0x5c, 0x74, 0x5d, 0}; static const UChar gRuleSet_name_char_pattern[] = { // [ _ \ p { L } \ p { N } ] 0x5b, 0x5f, 0x5c, 0x70, 0x7b, 0x4c, 0x7d, 0x5c, 0x70, 0x7b, 0x4e, 0x7d, 0x5d, 0}; static const UChar gRuleSet_digit_char_pattern[] = { // [ 0 - 9 ] 0x5b, 0x30, 0x2d, 0x39, 0x5d, 0}; static const UChar gRuleSet_name_start_char_pattern[] = { // [ _ \ p { L } ] 0x5b, 0x5f, 0x5c, 0x70, 0x7b, 0x4c, 0x7d, 0x5d, 0 }; static const UChar kAny[] = {0x61, 0x6e, 0x79, 0x00}; // "any" //---------------------------------------------------------------------------------------- // // Constructor. // //---------------------------------------------------------------------------------------- RBBIRuleScanner::RBBIRuleScanner(RBBIRuleBuilder *rb) { fRB = rb; fStackPtr = 0; fStack[fStackPtr] = 0; fNodeStackPtr = 0; fRuleNum = 0; fNodeStack[0] = NULL; fRuleSets[kRuleSet_rule_char-128] = NULL; fRuleSets[kRuleSet_white_space-128] = NULL; fRuleSets[kRuleSet_name_char-128] = NULL; fRuleSets[kRuleSet_name_start_char-128] = NULL; fRuleSets[kRuleSet_digit_char-128] = NULL; fSymbolTable = NULL; fSetTable = NULL; fScanIndex = 0; fNextIndex = 0; fReverseRule = FALSE; fLookAheadRule = FALSE; fLineNum = 1; fCharNum = 0; fQuoteMode = FALSE; if (U_FAILURE(*rb->fStatus)) { return; } // // Set up the constant Unicode Sets. // Note: These could be made static, lazily initialized, and shared among // all instances of RBBIRuleScanners. BUT this is quite a bit simpler, // and the time to build these few sets should be small compared to a // full break iterator build. fRuleSets[kRuleSet_rule_char-128] = new UnicodeSet(gRuleSet_rule_char_pattern, *rb->fStatus); fRuleSets[kRuleSet_white_space-128] = new UnicodeSet(gRuleSet_white_space_pattern, *rb->fStatus); fRuleSets[kRuleSet_name_char-128] = new UnicodeSet(gRuleSet_name_char_pattern, *rb->fStatus); fRuleSets[kRuleSet_name_start_char-128] = new UnicodeSet(gRuleSet_name_start_char_pattern, *rb->fStatus); fRuleSets[kRuleSet_digit_char-128] = new UnicodeSet(gRuleSet_digit_char_pattern, *rb->fStatus); if (U_FAILURE(*rb->fStatus)) { return; } fSymbolTable = new RBBISymbolTable(this, rb->fRules, *rb->fStatus); fSetTable = uhash_open(uhash_hashUnicodeString, uhash_compareUnicodeString, rb->fStatus); uhash_setValueDeleter(fSetTable, RBBISetTable_deleter); } //---------------------------------------------------------------------------------------- // // Destructor // //---------------------------------------------------------------------------------------- RBBIRuleScanner::~RBBIRuleScanner() { delete fRuleSets[kRuleSet_rule_char-128]; delete fRuleSets[kRuleSet_white_space-128]; delete fRuleSets[kRuleSet_name_char-128]; delete fRuleSets[kRuleSet_name_start_char-128]; delete fRuleSets[kRuleSet_digit_char-128]; delete fSymbolTable; if (fSetTable != NULL) { uhash_close(fSetTable); fSetTable = NULL; } #if 0 // TODO: does the rule builder class own this? // Delete the linked lest of USet nodes and the corresponding UnicodeSets. // (Deleting a node deletes its children, so deleting the head node of // this list will take out the whole list.) RBBINode *n, *nextN; for (n=fSetsListHead; n!=NULL; n=nextN) { nextN = n->fRightChild; delete n; } fSetsListHead = NULL; #endif // Node Stack. // Normally has one entry, which is the entire parse tree for the rules. // If errors occured, there may be additional subtrees left on the stack. while (fNodeStackPtr > 0) { delete fNodeStack[fNodeStackPtr]; fNodeStackPtr--; } } //---------------------------------------------------------------------------------------- // // doParseAction Do some action during rule parsing. // Called by the parse state machine. // Actions build the parse tree and Unicode Sets, // and maintain the parse stack for nested expressions. // // TODO: unify EParseAction and RBBI_RuleParseAction enum types. // They represent exactly the same thing. They're separate // only to work around enum forward declaration restrictions // in some compilers, while at the same time avoiding multiple // definitions problems. I'm sure that there's a better way. // //---------------------------------------------------------------------------------------- UBool RBBIRuleScanner::doParseActions(EParseAction action, RBBIRuleScanner::RBBIRuleChar &c) { int i = 0; RBBINode *n = NULL; UBool returnVal = TRUE; switch ((RBBI_RuleParseAction)action) { case doExprStart: pushNewNode(RBBINode::opStart); fRuleNum++; break; case doExprOrOperator: { fixOpStack(RBBINode::precOpCat); RBBINode *operandNode = fNodeStack[fNodeStackPtr--]; RBBINode *orNode = pushNewNode(RBBINode::opOr); orNode->fLeftChild = operandNode; operandNode->fParent = orNode; } break; case doExprCatOperator: // concatenation operator. // For the implicit concatenation of adjacent terms in an expression that are // not separated by any other operator. Action is invoked between the // actions for the two terms. { fixOpStack(RBBINode::precOpCat); RBBINode *operandNode = fNodeStack[fNodeStackPtr--]; RBBINode *catNode = pushNewNode(RBBINode::opCat); catNode->fLeftChild = operandNode; operandNode->fParent = catNode; } break; case doLParen: // Open Paren. // The openParen node is a dummy operation type with a low precedence, // which has the affect of ensuring that any real binary op that // follows within the parens binds more tightly to the operands than // stuff outside of the parens. pushNewNode(RBBINode::opLParen); break; case doExprRParen: fixOpStack(RBBINode::precLParen); break; case doNOP: break; case doStartAssign: // We've just scanned "$variable = " // The top of the node stack has the $variable ref node. // Save the start position of the RHS text in the StartExpression node // that precedes the $variableReference node on the stack. // This will eventually be used when saving the full $variable replacement // text as a string. n = fNodeStack[fNodeStackPtr-1]; n->fFirstPos = fNextIndex; // move past the '=' // Push a new start-of-expression node; needed to keep parse of the // RHS expression happy. pushNewNode(RBBINode::opStart); break; case doEndAssign: { // We have reached the end of an assignement statement. // Current scan char is the ';' that terminates the assignment. // Terminate expression, leaves expression parse tree rooted in TOS node. fixOpStack(RBBINode::precStart); RBBINode *startExprNode = fNodeStack[fNodeStackPtr-2]; RBBINode *varRefNode = fNodeStack[fNodeStackPtr-1]; RBBINode *RHSExprNode = fNodeStack[fNodeStackPtr]; // Save original text of right side of assignment, excluding the terminating ';' // in the root of the node for the right-hand-side expression. RHSExprNode->fFirstPos = startExprNode->fFirstPos; RHSExprNode->fLastPos = fScanIndex; fRB->fRules.extractBetween(RHSExprNode->fFirstPos, RHSExprNode->fLastPos, RHSExprNode->fText); // Expression parse tree becomes l. child of the $variable reference node. varRefNode->fLeftChild = RHSExprNode; RHSExprNode->fParent = varRefNode; // Make a symbol table entry for the $variableRef node. fSymbolTable->addEntry(varRefNode->fText, varRefNode, *fRB->fStatus); // Clean up the stack. delete startExprNode; fNodeStackPtr-=3; break; } case doEndOfRule: { fixOpStack(RBBINode::precStart); // Terminate expression, leaves expression if (U_FAILURE(*fRB->fStatus)) { // parse tree rooted in TOS node. break; } if (fRB->fDebugEnv && strstr(fRB->fDebugEnv, "rtree")) {printNodeStack("end of rule");} assert(fNodeStackPtr == 1); // If this rule includes a look-ahead '/', add a endMark node to the // expression tree. if (fLookAheadRule) { RBBINode *thisRule = fNodeStack[fNodeStackPtr]; RBBINode *endNode = pushNewNode(RBBINode::endMark); RBBINode *catNode = pushNewNode(RBBINode::opCat); fNodeStackPtr -= 2; catNode->fLeftChild = thisRule; catNode->fRightChild = endNode; fNodeStack[fNodeStackPtr] = catNode; endNode->fVal = fRuleNum; endNode->fLookAheadEnd = TRUE; } // All rule expressions are ORed together. // The ';' that terminates an expression really just functions as a '|' with // a low operator prededence. // // Forward and reverse rules are collected separately. Or this rule into // the appropriate group of them. // RBBINode **destRules = (fReverseRule? &fRB->fReverseTree : &fRB->fForwardTree); if (*destRules != NULL) { // This is not the first rule encounted. // OR previous stuff (from *destRules) // with the current rule expression (on the Node Stack) // with the resulting OR expression going to *destRules // RBBINode *thisRule = fNodeStack[fNodeStackPtr]; RBBINode *prevRules = *destRules; RBBINode *orNode = pushNewNode(RBBINode::opOr); orNode->fLeftChild = prevRules; prevRules->fParent = orNode; orNode->fRightChild = thisRule; thisRule->fParent = orNode; *destRules = orNode; } else { // This is the first rule encountered (for this direction). // Just move its parse tree from the stack to *destRules. *destRules = fNodeStack[fNodeStackPtr]; } fReverseRule = FALSE; // in preparation for the next rule. fLookAheadRule = FALSE; fNodeStackPtr = 0; } break; case doRuleError: error(U_BRK_RULE_SYNTAX); returnVal = FALSE; break; case doVariableNameExpectedErr: error(U_BRK_RULE_SYNTAX); break; // // Unary operands + ? * // These all appear after the operand to which they apply. // When we hit one, the operand (may be a whole sub expression) // will be on the top of the stack. // Unary Operator becomes TOS, with the old TOS as its one child. case doUnaryOpPlus: { RBBINode *operandNode = fNodeStack[fNodeStackPtr--]; RBBINode *plusNode = pushNewNode(RBBINode::opPlus); plusNode->fLeftChild = operandNode; operandNode->fParent = plusNode; } break; case doUnaryOpQuestion: { RBBINode *operandNode = fNodeStack[fNodeStackPtr--]; RBBINode *qNode = pushNewNode(RBBINode::opQuestion); qNode->fLeftChild = operandNode; operandNode->fParent = qNode; } break; case doUnaryOpStar: { RBBINode *operandNode = fNodeStack[fNodeStackPtr--]; RBBINode *starNode = pushNewNode(RBBINode::opStar); starNode->fLeftChild = operandNode; operandNode->fParent = starNode; } break; case doRuleChar: // A "Rule Character" is any single character that is a literal part // of the regular expression. Like a, b and c in the expression "(abc*) | [:L:]" // These are pretty uncommon in break rules; the terms are more commonly // sets. To keep things uniform, treat these characters like as // sets that just happen to contain only one character. { n = pushNewNode(RBBINode::setRef); findSetFor(fC.fChar, n); n->fFirstPos = fScanIndex; n->fLastPos = fNextIndex; fRB->fRules.extractBetween(n->fFirstPos, n->fLastPos, n->fText); break; } case doDotAny: // scanned a ".", meaning match any single character. { n = pushNewNode(RBBINode::setRef); findSetFor(kAny, n); n->fFirstPos = fScanIndex; n->fLastPos = fNextIndex; fRB->fRules.extractBetween(n->fFirstPos, n->fLastPos, n->fText); break; } break; case doSlash: // Scanned a '/', which identifies a look-ahead break position in a rule. n = pushNewNode(RBBINode::lookAhead); n->fVal = fRuleNum; n->fFirstPos = fScanIndex; n->fLastPos = fNextIndex; fRB->fRules.extractBetween(n->fFirstPos, n->fLastPos, n->fText); fLookAheadRule = TRUE; break; case doStartTagValue: // Scanned a '{', the opening delimiter for a tag value within a rule. n = pushNewNode(RBBINode::tag); n->fVal = 0; n->fFirstPos = fScanIndex; n->fLastPos = fNextIndex; break; case doTagDigit: // Just scanned a decimal digit that's part of a tag value { n = fNodeStack[fNodeStackPtr]; uint32_t v = u_charDigitValue(fC.fChar); assert(v >= 0); n->fVal = n->fVal*10 + v; break; } case doTagValue: n = fNodeStack[fNodeStackPtr]; n->fLastPos = fNextIndex; fRB->fRules.extractBetween(n->fFirstPos, n->fLastPos, n->fText); break; case doReverseDir: fReverseRule = TRUE; break; case doStartVariableName: n = pushNewNode(RBBINode::varRef); if (U_FAILURE(*fRB->fStatus)) {break;}; n->fFirstPos = fScanIndex; break; case doEndVariableName: n = fNodeStack[fNodeStackPtr]; if (n==NULL || n->fType != RBBINode::varRef) { error(U_BRK_INTERNAL_ERROR); break; } n->fLastPos = fScanIndex; fRB->fRules.extractBetween(n->fFirstPos+1, n->fLastPos, n->fText); // Look the newly scanned name up in the symbol table // If there's an entry, set the l. child of the var ref to the replacement expression. // (We also pass through here when scanning assignments, but no harm is done, other // than a slight wasted effort that seems hard to avoid. Lookup will be null) n->fLeftChild = fSymbolTable->lookupNode(n->fText); break; case doCheckVarDef: n = fNodeStack[fNodeStackPtr]; if (n->fLeftChild == NULL) { error(U_BRK_UNDEFINED_VARIABLE); returnVal = FALSE; } break; case doExprFinished: break; case doRuleErrorAssignExpr: error(U_BRK_ASSIGN_ERROR); returnVal = FALSE; break; case doExit: returnVal = FALSE; break; case doScanUnicodeSet: scanSet(); break; default: error(U_BRK_INTERNAL_ERROR); returnVal = FALSE; break; } return returnVal; }; //---------------------------------------------------------------------------------------- // // Error Report a rule parse error. // Only report it if no previous error has been recorded. // //---------------------------------------------------------------------------------------- void RBBIRuleScanner::error(UErrorCode e) { if (U_SUCCESS(*fRB->fStatus)) { *fRB->fStatus = e; fRB->fParseError->line = fLineNum; fRB->fParseError->offset = fCharNum; fRB->fParseError->preContext[0] = 0; fRB->fParseError->preContext[0] = 0; } } //---------------------------------------------------------------------------------------- // // fixOpStack The parse stack holds partially assembled chunks of the parse tree. // An entry on the stack may be as small as a single setRef node, // or as large as the parse tree // for an entire expression (this will be the one item left on the stack // when the parsing of an RBBI rule completes. // // This function is called when a binary operator is encountered. // It looks back up the stack for operators that are not yet associated // with a right operand, and if the precedence of the stacked operator >= // the precedence of the current operator, binds the operand left, // to the previously encountered operator. // //---------------------------------------------------------------------------------------- void RBBIRuleScanner::fixOpStack(RBBINode::OpPrecedence p) { RBBINode *n; // printNodeStack("entering fixOpStack()"); for (;;) { n = fNodeStack[fNodeStackPtr-1]; // an operator node if (n->fPrecedence == 0) { fprintf(stderr, "RBBIRuleScanner::fixOpStack, bad operator node\n"); error(U_BRK_INTERNAL_ERROR); return; } if (n->fPrecedence < p || n->fPrecedence <= RBBINode::precLParen) { // The most recent operand goes with the current operator, // not with the previously stacked one. break; } // Stack operator is a binary op ( '|' or concatenation) // TOS operand becomes right child of this operator. // Resulting subexpression becomes the TOS operand. n->fRightChild = fNodeStack[fNodeStackPtr]; fNodeStack[fNodeStackPtr]->fParent = n; fNodeStackPtr--; // printNodeStack("looping in fixOpStack() "); } if (p <= RBBINode::precLParen) { // Scan is at a right paren or end of expression. // The scanned item must match the stack, or else there was an error. // Discard the left paren (or start expr) node from the stack, // leaving the completed (sub)expression as TOS. if (n->fPrecedence != p) { // Right paren encountered matched start of expression node, or // end of expression matched with a left paren node. error(U_BRK_MISMATCHED_PAREN); } fNodeStack[fNodeStackPtr-1] = fNodeStack[fNodeStackPtr]; fNodeStackPtr--; // Delete the now-discarded LParen or Start node. delete n; } // printNodeStack("leaving fixOpStack()"); } //---------------------------------------------------------------------------------------- // // findSetFor given a UnicodeString, // - find the corresponding Unicode Set (uset node) // (create one if necessary) // - Set fLeftChild of the caller's node (should be a setRef node) // to the uset node // Maintain a hash table of uset nodes, so the same one is always used // for the same string. // If a "to adopt" set is provided and we haven't seen this key before, // add the provided set to the hash table. // If the string is one (32 bit) char in length, the set contains // just one element which is the char in question. // If the string is "any", return a set containing all chars. // //---------------------------------------------------------------------------------------- U_CDECL_BEGIN static void U_EXPORT2 U_CALLCONV RBBISetTable_deleter(void *p) { RBBISetTableEl *px = (RBBISetTableEl *)p; delete px->key; // Note: px->val is owned by the linked list "fSetsListHead" in scanner. // Don't delete the value nodes here. uprv_free(px); }; U_CDECL_END void RBBIRuleScanner::findSetFor(const UnicodeString &s, RBBINode *node, UnicodeSet *setToAdopt) { RBBISetTableEl *el; // First check whether we've already cached a set for this string. // If so, just use the cached set in the new node. // delete any set provided by the caller, since we own it. el = (RBBISetTableEl *)uhash_get(fSetTable, &s); if (el != NULL) { delete setToAdopt; node->fLeftChild = el->val; assert(node->fLeftChild->fType == RBBINode::uset); return; } // Haven't seen this set before. // If the caller didn't provide us with a prebuilt set, // create a new UnicodeSet now. if (setToAdopt == NULL) { if (s.compare(kAny, -1) == 0) { setToAdopt = new UnicodeSet(0x000000, 0x10ffff); } else { UChar32 c; c = s.char32At(0); setToAdopt = new UnicodeSet(c, c); } } // // Make a new uset node to refer to this UnicodeSet // This new uset node becomes the child of the caller's setReference node. // RBBINode *usetNode = new RBBINode(RBBINode::uset); usetNode->fInputSet = setToAdopt; usetNode->fParent = node; node->fLeftChild = usetNode; usetNode->fText = s; // // Link the new uset node into the list of all uset nodes. // usetNode->fRightChild = fRB->fSetsListHead; fRB->fSetsListHead = usetNode; // // Add the new set to the set hash table. // el = (RBBISetTableEl *)uprv_malloc(sizeof(RBBISetTableEl)); UnicodeString *tkey = new UnicodeString(s); if (tkey == NULL || el == NULL || setToAdopt == NULL) { error(U_MEMORY_ALLOCATION_ERROR); return; } el->key = tkey; el->val = usetNode; uhash_put(fSetTable, el->key, el, fRB->fStatus); return; } // // Assorted Unicode character constants. // Numeric because there is no portable way to enter them as literals. // (Think EBCDIC). // static const UChar chCR = 0x0d; // New lines, for terminating comments. static const UChar chLF = 0x0a; static const UChar chNEL = 0x85; // NEL newline variant static const UChar chLS = 0x2028; // Unicode Line Separator static const UChar chApos = 0x27; // single quote, for quoted chars. static const UChar chPound = 0x23; // '#', introduces a comment. static const UChar chBackSlash = 0x5c; // '\' introduces a char escape static const UChar chLParen = 0x28; static const UChar chRParen = 0x29; //---------------------------------------------------------------------------------------- // // nextCharLL Low Level Next Char from rule input source. // Get a char from the input character iterator, // keep track of input position for error reporting. // //---------------------------------------------------------------------------------------- UChar32 RBBIRuleScanner::nextCharLL() { UChar32 ch; if (fNextIndex >= fRB->fRules.length()) { return (UChar32)-1; } ch = fRB->fRules.char32At(fNextIndex); fNextIndex = fRB->fRules.moveIndex32(fNextIndex, 1); if (ch == chCR || ch == chNEL || ch == chLS || ch == chLF && fLastChar != chCR) { // Character is starting a new line. Bump up the line number, and // reset the column to 0. fLineNum++; fCharNum=0; if (fQuoteMode) { error(U_BRK_NEW_LINE_IN_QUOTED_STRING); fQuoteMode = FALSE; } } else { // Character is not starting a new line. Except in the case of a // LF following a CR, increment the column position. if (ch != chLF) { fCharNum++; } } fLastChar = ch; return ch; } //--------------------------------------------------------------------------------- // // nextChar for rules scanning. At this level, we handle stripping // out comments and processing backslash character escapes. // The rest of the rules grammar is handled at the next level up. // //--------------------------------------------------------------------------------- void RBBIRuleScanner::nextChar(RBBIRuleChar &c) { // Unicode Character constants needed for the processing done by nextChar(), // in hex because literals wont work on EBCDIC machines. fScanIndex = fNextIndex; c.fChar = nextCharLL(); c.fEscaped = FALSE; // // check for '' sequence. // These are recognized in all contexts, whether in quoted text or not. // if (c.fChar == chApos) { if (fRB->fRules.char32At(fNextIndex) == chApos) { c.fChar = nextCharLL(); // get nextChar officially so character counts c.fEscaped = TRUE; // stay correct. } else { // Single quote, by itself. // Toggle quoting mode. // Return either '(' or ')', because quotes cause a grouping of the quoted text. fQuoteMode = !fQuoteMode; if (fQuoteMode == TRUE) { c.fChar = chLParen; } else { c.fChar = chRParen; } c.fEscaped = FALSE; // The paren that we return is not escaped. return; } } if (fQuoteMode) { c.fEscaped = TRUE; } else { // We are not in a 'quoted region' of the source. // if (c.fChar == chPound) { // Start of a comment. Consume the rest of it. // The new-line char that terminates the comment is always returned. // It will be treated as white-space, and serves to break up anything // that might otherwise incorrectly clump together with a comment in // the middle (a variable name, for example.) for (;;) { c.fChar = nextCharLL(); if (c.fChar == -1 || // EOF c.fChar == chCR || c.fChar == chLF || c.fChar == chNEL || c.fChar == chLS) {break;} } } if (c.fChar == (UChar32)-1) { return; } // // check for backslash escaped characters. // Use UnicodeString::unescapeAt() to handle them. // if (c.fChar == chBackSlash) { c.fEscaped = TRUE; int32_t startX = fNextIndex; c.fChar = fRB->fRules.unescapeAt(fNextIndex); if (fNextIndex == startX) { error(U_BRK_HEX_DIGITS_EXPECTED); } fCharNum += fNextIndex-startX; } } // putc(c.fChar, stdout); } //--------------------------------------------------------------------------------- // // Parse RBBI rules. The state machine for rules parsing is here. // The state tables are hand-written in the file TODO.txt, // and converted to the form used here by a perl // script rbbicst.pl // //--------------------------------------------------------------------------------- void RBBIRuleScanner::parse() { uint16_t state; const RBBIRuleTableEl *tableEl; if (U_FAILURE(*fRB->fStatus)) { return; } state = 1; nextChar(fC); // // Main loop for the rule parsing state machine. // Runs once per state transition. // Each time through optionally performs, depending on the state table, // - an advance to the the next input char // - an action to be performed. // - pushing or popping a state to/from the local state return stack. // for (;;) { // Bail out if anything has gone wrong. // RBBI rule file parsing stops on the first error encountered. if (U_FAILURE(*fRB->fStatus)) { break; } // Quit if state == 0. This is the normal way to exit the state machine. // if (state == 0) { break; } // Find the state table element that matches the input char from the rule, or the // class of the input character. Start with the first table row for this // state, then linearly scan forward until we find a row that matches the // character. The last row for each state always matches all characters, so // the search will stop there, if not before. // tableEl = &gRuleParseStateTable[state]; if (fRB->fDebugEnv && strstr(fRB->fDebugEnv, "scan")) { printf("char, line, col = (\'%c\', %d, %d) state=%s ", fC.fChar, fLineNum, fCharNum, RBBIRuleStateNames[state]); } for (;;) { if (fRB->fDebugEnv && strstr(fRB->fDebugEnv, "scan")) { printf(".");} if (tableEl->fCharClass < 127 && tableEl->fCharClass == fC.fChar) { // Table row specified an individual character, not a set, and // the input character matched it. break; } if (tableEl->fCharClass == 255) { // Table row specified default, match anything character class. break; } if (tableEl->fCharClass == 254 && fC.fEscaped) { // Table row specified "escaped" and the char was escaped. break; } if (tableEl->fCharClass == 253 && fC.fEscaped && (fC.fChar == 0x50 || fC.fChar == 0x70 )) { // Table row specified "escaped P" and the char is either 'p' or 'P'. break; } if (tableEl->fCharClass == 252 && fC.fChar == -1) { // Table row specified eof and we hit eof on the input. break; } if (tableEl->fCharClass >= 128 && tableEl->fCharClass < 240 && fC.fChar != -1) { UnicodeSet *uniset = fRuleSets[tableEl->fCharClass-128]; if (uniset->contains(fC.fChar)) { // Table row specified a character class, or set of characters, // and the current char matches it. break; } } // No match on this row, advance to the next row for this state, tableEl++; } if (fRB->fDebugEnv && strstr(fRB->fDebugEnv, "scan")) { printf("\n");} // // We've found the row of the state table that matches the current input // character from the rules string. // Perform any action specified by this row in the state table. if (doParseActions((EParseAction)tableEl->fAction, fC) == FALSE) { // Break out of the state machine loop if the // the action signalled some kind of error, or // the action was to exit, occurs on normal end-of-rules-input. break; } if (tableEl->fPushState != 0) { fStackPtr++; if (fStackPtr >= kStackSize) { error(U_BRK_INTERNAL_ERROR); fprintf(stderr, "RBBIRuleScanner::parse() - state stack overflow.\n"); fStackPtr--; } fStack[fStackPtr] = tableEl->fPushState; } if (tableEl->fNextChar) { nextChar(fC); } // Get the next state from the table entry, or from the // state stack if the next state was specified as "pop". if (tableEl->fNextState != 255) { state = tableEl->fNextState; } else { state = fStack[fStackPtr]; fStackPtr--; if (fStackPtr < 0) { error(U_BRK_INTERNAL_ERROR); fprintf(stderr, "RBBIRuleScanner::parse() - state stack underflow.\n"); fStackPtr++; } } } // // If there were NO user specified reverse rules, set up the equivalent of ".*;" // if (fRB->fReverseTree == NULL) { fRB->fReverseTree = pushNewNode(RBBINode::opStar); RBBINode *operand = pushNewNode(RBBINode::setRef); findSetFor(kAny, operand); fRB->fReverseTree->fLeftChild = operand; operand->fParent = fRB->fReverseTree; fNodeStackPtr -= 2; } // // Parsing of the input RBBI rules is complete. // We now have a parse tree for the rule expressions // and a list of all UnicodeSets that are referenced. // if (fRB->fDebugEnv && strstr(fRB->fDebugEnv, "symbols")) {fSymbolTable->print();} if (fRB->fDebugEnv && strstr(fRB->fDebugEnv, "ptree")) { printf("Completed Forward Rules Parse Tree...\n"); fRB->fForwardTree->printTree(); printf("\nCompleted Reverse Rules Parse Tree...\n"); fRB->fReverseTree->printTree(); } } //--------------------------------------------------------------------------------- // // printNodeStack for debugging... // //--------------------------------------------------------------------------------- void RBBIRuleScanner::printNodeStack(const char *title) { int i; printf("%s. Dumping node stack...\n", title); for (i=fNodeStackPtr; i>0; i--) {fNodeStack[i]->printTree();}; } //--------------------------------------------------------------------------------- // // pushNewNode create a new RBBINode of the specified type and push it // onto the stack of nodes. // //--------------------------------------------------------------------------------- RBBINode *RBBIRuleScanner::pushNewNode(RBBINode::NodeType t) { fNodeStackPtr++; if (fNodeStackPtr >= kStackSize) { error(U_BRK_INTERNAL_ERROR); fprintf(stderr, "RBBIRuleScanner::pushNewNode - stack overflow.\n"); *fRB->fStatus = U_BRK_INTERNAL_ERROR; return NULL; } fNodeStack[fNodeStackPtr] = new RBBINode(t); if (fNodeStack[fNodeStackPtr] == NULL) { *fRB->fStatus = U_MEMORY_ALLOCATION_ERROR; } return fNodeStack[fNodeStackPtr]; }; //--------------------------------------------------------------------------------- // // scanSet Construct a UnicodeSet from the text at the current scan // position. Advance the scan position to the first character // after the set. // // A new RBBI setref node referring to the set is pushed onto the node // stack. // // The scan position is normally under the control of the state machine // that controls rule parsing. UnicodeSets, however, are parsed by // the UnicodeSet constructor, not by the RBBI rule parser. // //--------------------------------------------------------------------------------- void RBBIRuleScanner::scanSet() { UnicodeSet *uset; ParsePosition pos; int errorPos = -1; int startPos; int i; if (U_FAILURE(*fRB->fStatus)) { return; } pos.setIndex(fScanIndex); startPos = fScanIndex; UErrorCode localStatus = U_ZERO_ERROR; uset = new UnicodeSet(fRB->fRules, pos, *fSymbolTable, localStatus); if (U_FAILURE(localStatus)) { // TODO: Get more accurate position of the error from UnicodeSet's return info. // UnicodeSet appears to not be reporting correctly at this time. printf("UnicodeSet parse postion.ErrorIndex = %d\n", pos.getIndex()); error(localStatus); return; } // Advance the RBBI parse postion over the UnicodeSet pattern. // Don't just set fScanIndex because the line/char positions maintained // for error reporting would be thrown off. i = pos.getIndex(); for (;;) { if (fNextIndex >= i) { break; } nextCharLL(); } if (U_SUCCESS(*fRB->fStatus)) { RBBINode *n; n = pushNewNode(RBBINode::setRef); n->fFirstPos = startPos; n->fLastPos = fNextIndex; fRB->fRules.extractBetween(n->fFirstPos, n->fLastPos, n->fText); // findSetFor() serves several purposes here: // - Adopts storage for the UnicodeSet, will be responsible for deleting. // - Mantains collection of all sets in use, needed later for establishing // character categories for run time engine. // - Eliminates mulitiple instances of the same set. // - Creates a new uset node if necessary (if this isn't a duplicate.) findSetFor(n->fText, n, uset); } }; U_NAMESPACE_END