1//
2//  rbbiscan.h
3//
4//  Copyright (C) 2002-2008, International Business Machines Corporation and others.
5//  All Rights Reserved.
6//
7//  This file contains declarations for class RBBIRuleScanner
8//
9
10
11#ifndef RBBISCAN_H
12#define RBBISCAN_H
13
14#include "unicode/utypes.h"
15#include "unicode/uobject.h"
16#include "unicode/rbbi.h"
17#include "unicode/uniset.h"
18#include "unicode/parseerr.h"
19#include "uhash.h"
20#include "uvector.h"
21#include "unicode/symtable.h"// For UnicodeSet parsing, is the interface that
22                          //    looks up references to $variables within a set.
23#include "rbbinode.h"
24//#include "rbbitblb.h"
25
26
27
28U_NAMESPACE_BEGIN
29
30class   RBBIRuleBuilder;
31class   RBBISymbolTable;
32
33
34//--------------------------------------------------------------------------------
35//
36//  class RBBIRuleScanner does the lowest level, character-at-a-time
37//                        scanning of break iterator rules.
38//
39//                        The output of the scanner is parse trees for
40//                        the rule expressions and a list of all Unicode Sets
41//                        encountered.
42//
43//--------------------------------------------------------------------------------
44
45class RBBIRuleScanner : public UMemory {
46public:
47
48    enum {
49        kStackSize = 100            // The size of the state stack for
50    };                              //   rules parsing.  Corresponds roughly
51                                    //   to the depth of parentheses nesting
52                                    //   that is allowed in the rules.
53
54    struct RBBIRuleChar {
55        UChar32             fChar;
56        UBool               fEscaped;
57    };
58
59    RBBIRuleScanner(RBBIRuleBuilder  *rb);
60
61
62    virtual    ~RBBIRuleScanner();
63
64    void        nextChar(RBBIRuleChar &c);          // Get the next char from the input stream.
65                                                    // Return false if at end.
66
67    UBool       push(const RBBIRuleChar &c);        // Push (unget) one character.
68                                                    //   Only a single character may be pushed.
69
70    void        parse();                            // Parse the rules, generating two parse
71                                                    //   trees, one each for the forward and
72                                                    //   reverse rules,
73                                                    //   and a list of UnicodeSets encountered.
74
75    /**
76     * Return a rules string without unnecessary
77     * characters.
78     */
79    static UnicodeString stripRules(const UnicodeString &rules);
80private:
81
82    UBool       doParseActions(int32_t a);
83    void        error(UErrorCode e);                   // error reporting convenience function.
84    void        fixOpStack(RBBINode::OpPrecedence p);
85                                                       //   a character.
86    void        findSetFor(const UnicodeString &s, RBBINode *node, UnicodeSet *setToAdopt = NULL);
87
88    UChar32     nextCharLL();
89#ifdef RBBI_DEBUG
90    void        printNodeStack(const char *title);
91#endif
92    RBBINode    *pushNewNode(RBBINode::NodeType  t);
93    void        scanSet();
94
95
96    RBBIRuleBuilder               *fRB;              // The rule builder that we are part of.
97
98    int32_t                       fScanIndex;        // Index of current character being processed
99                                                     //   in the rule input string.
100    int32_t                       fNextIndex;        // Index of the next character, which
101                                                     //   is the first character not yet scanned.
102    UBool                         fQuoteMode;        // Scan is in a 'quoted region'
103    int32_t                       fLineNum;          // Line number in input file.
104    int32_t                       fCharNum;          // Char position within the line.
105    UChar32                       fLastChar;         // Previous char, needed to count CR-LF
106                                                     //   as a single line, not two.
107
108    RBBIRuleChar                  fC;                // Current char for parse state machine
109                                                     //   processing.
110    UnicodeString                 fVarName;          // $variableName, valid when we've just
111                                                     //   scanned one.
112
113    RBBIRuleTableEl               **fStateTable;     // State Transition Table for RBBI Rule
114                                                     //   parsing.  index by p[state][char-class]
115
116    uint16_t                      fStack[kStackSize];  // State stack, holds state pushes
117    int32_t                       fStackPtr;           //  and pops as specified in the state
118                                                       //  transition rules.
119
120    RBBINode                      *fNodeStack[kStackSize]; // Node stack, holds nodes created
121                                                           //  during the parse of a rule
122    int32_t                        fNodeStackPtr;
123
124
125    UBool                          fReverseRule;     // True if the rule currently being scanned
126                                                     //  is a reverse direction rule (if it
127                                                     //  starts with a '!')
128
129    UBool                          fLookAheadRule;   // True if the rule includes a '/'
130                                                     //   somewhere within it.
131
132    RBBISymbolTable               *fSymbolTable;     // symbol table, holds definitions of
133                                                     //   $variable symbols.
134
135    UHashtable                    *fSetTable;        // UnicocodeSet hash table, holds indexes to
136                                                     //   the sets created while parsing rules.
137                                                     //   The key is the string used for creating
138                                                     //   the set.
139
140    UnicodeSet                     fRuleSets[10];    // Unicode Sets that are needed during
141                                                     //  the scanning of RBBI rules.  The
142                                                     //  indicies for these are assigned by the
143                                                     //  perl script that builds the state tables.
144                                                     //  See rbbirpt.h.
145
146    int32_t                        fRuleNum;         // Counts each rule as it is scanned.
147
148    int32_t                        fOptionStart;     // Input index of start of a !!option
149                                                     //   keyword, while being scanned.
150
151    UnicodeSet *gRuleSet_rule_char;
152    UnicodeSet *gRuleSet_white_space;
153    UnicodeSet *gRuleSet_name_char;
154    UnicodeSet *gRuleSet_name_start_char;
155
156    RBBIRuleScanner(const RBBIRuleScanner &other); // forbid copying of this class
157    RBBIRuleScanner &operator=(const RBBIRuleScanner &other); // forbid copying of this class
158};
159
160U_NAMESPACE_END
161
162#endif
163