// © 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.

    /**

     * 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

                                                     //  indicies 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