virtualx-engine/thirdparty/icu4c/common/rbbiscan.h
2021-10-28 09:15:28 +03:00

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// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
//
// rbbiscan.h
//
// Copyright (C) 2002-2016, International Business Machines Corporation and others.
// All Rights Reserved.
//
// This file contains declarations for class RBBIRuleScanner
//
#ifndef RBBISCAN_H
#define RBBISCAN_H
#include "unicode/utypes.h"
#include "unicode/uobject.h"
#include "unicode/rbbi.h"
#include "unicode/uniset.h"
#include "unicode/parseerr.h"
#include "uhash.h"
#include "uvector.h"
#include "unicode/symtable.h"// For UnicodeSet parsing, is the interface that
// looks up references to $variables within a set.
#include "rbbinode.h"
#include "rbbirpt.h"
U_NAMESPACE_BEGIN
class RBBIRuleBuilder;
class RBBISymbolTable;
//--------------------------------------------------------------------------------
//
// class RBBIRuleScanner does the lowest level, character-at-a-time
// scanning of break iterator rules.
//
// The output of the scanner is parse trees for
// the rule expressions and a list of all Unicode Sets
// encountered.
//
//--------------------------------------------------------------------------------
class RBBIRuleScanner : public UMemory {
public:
enum {
kStackSize = 100 // The size of the state stack for
}; // rules parsing. Corresponds roughly
// to the depth of parentheses nesting
// that is allowed in the rules.
struct RBBIRuleChar {
UChar32 fChar;
UBool fEscaped;
RBBIRuleChar() : fChar(0), fEscaped(false) {}
};
RBBIRuleScanner(RBBIRuleBuilder *rb);
virtual ~RBBIRuleScanner();
void nextChar(RBBIRuleChar &c); // Get the next char from the input stream.
// Return false if at end.
UBool push(const RBBIRuleChar &c); // Push (unget) one character.
// Only a single character may be pushed.
void parse(); // Parse the rules, generating two parse
// trees, one each for the forward and
// reverse rules,
// and a list of UnicodeSets encountered.
int32_t numRules(); // Return the number of rules that have been seen.
/**
* Return a rules string without unnecessary
* characters.
*/
static UnicodeString stripRules(const UnicodeString &rules);
private:
UBool doParseActions(int32_t a);
void error(UErrorCode e); // error reporting convenience function.
void fixOpStack(RBBINode::OpPrecedence p);
// a character.
void findSetFor(const UnicodeString &s, RBBINode *node, UnicodeSet *setToAdopt = NULL);
UChar32 nextCharLL();
#ifdef RBBI_DEBUG
void printNodeStack(const char *title);
#endif
RBBINode *pushNewNode(RBBINode::NodeType t);
void scanSet();
RBBIRuleBuilder *fRB; // The rule builder that we are part of.
int32_t fScanIndex; // Index of current character being processed
// in the rule input string.
int32_t fNextIndex; // Index of the next character, which
// is the first character not yet scanned.
UBool fQuoteMode; // Scan is in a 'quoted region'
int32_t fLineNum; // Line number in input file.
int32_t fCharNum; // Char position within the line.
UChar32 fLastChar; // Previous char, needed to count CR-LF
// as a single line, not two.
RBBIRuleChar fC; // Current char for parse state machine
// processing.
UnicodeString fVarName; // $variableName, valid when we've just
// scanned one.
RBBIRuleTableEl **fStateTable; // State Transition Table for RBBI Rule
// parsing. index by p[state][char-class]
uint16_t fStack[kStackSize]; // State stack, holds state pushes
int32_t fStackPtr; // and pops as specified in the state
// transition rules.
RBBINode *fNodeStack[kStackSize]; // Node stack, holds nodes created
// during the parse of a rule
int32_t fNodeStackPtr;
UBool fReverseRule; // True if the rule currently being scanned
// is a reverse direction rule (if it
// starts with a '!')
UBool fLookAheadRule; // True if the rule includes a '/'
// somewhere within it.
UBool fNoChainInRule; // True if the current rule starts with a '^'.
RBBISymbolTable *fSymbolTable; // symbol table, holds definitions of
// $variable symbols.
UHashtable *fSetTable; // UnicocodeSet hash table, holds indexes to
// the sets created while parsing rules.
// The key is the string used for creating
// the set.
UnicodeSet fRuleSets[10]; // Unicode Sets that are needed during
// the scanning of RBBI rules. The
// indices for these are assigned by the
// perl script that builds the state tables.
// See rbbirpt.h.
int32_t fRuleNum; // Counts each rule as it is scanned.
int32_t fOptionStart; // Input index of start of a !!option
// keyword, while being scanned.
UnicodeSet *gRuleSet_rule_char;
UnicodeSet *gRuleSet_white_space;
UnicodeSet *gRuleSet_name_char;
UnicodeSet *gRuleSet_name_start_char;
RBBIRuleScanner(const RBBIRuleScanner &other); // forbid copying of this class
RBBIRuleScanner &operator=(const RBBIRuleScanner &other); // forbid copying of this class
};
U_NAMESPACE_END
#endif