1// © 2016 and later: Unicode, Inc. and others.
2// License & terms of use: http://www.unicode.org/copyright.html
3//
4// rbbiscan.h
5//
6// Copyright (C) 2002-2016, International Business Machines Corporation and others.
7// All Rights Reserved.
8//
9// This file contains declarations for class RBBIRuleScanner
10//
11
12
13#ifndef RBBISCAN_H
14#define RBBISCAN_H
15
16#include "unicode/utypes.h"
17#include "unicode/uobject.h"
18#include "unicode/rbbi.h"
19#include "unicode/uniset.h"
20#include "unicode/parseerr.h"
21#include "uhash.h"
22#include "uvector.h"
23#include "unicode/symtable.h"// For UnicodeSet parsing, is the interface that
24 // looks up references to $variables within a set.
25#include "rbbinode.h"
26#include "rbbirpt.h"
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 RBBIRuleChar() : fChar(0), fEscaped(FALSE) {}
58 };
59
60 RBBIRuleScanner(RBBIRuleBuilder *rb);
61
62
63 virtual ~RBBIRuleScanner();
64
65 void nextChar(RBBIRuleChar &c); // Get the next char from the input stream.
66 // Return false if at end.
67
68 UBool push(const RBBIRuleChar &c); // Push (unget) one character.
69 // Only a single character may be pushed.
70
71 void parse(); // Parse the rules, generating two parse
72 // trees, one each for the forward and
73 // reverse rules,
74 // and a list of UnicodeSets encountered.
75
76 /**
77 * Return a rules string without unnecessary
78 * characters.
79 */
80 static UnicodeString stripRules(const UnicodeString &rules);
81private:
82
83 UBool doParseActions(int32_t a);
84 void error(UErrorCode e); // error reporting convenience function.
85 void fixOpStack(RBBINode::OpPrecedence p);
86 // a character.
87 void findSetFor(const UnicodeString &s, RBBINode *node, UnicodeSet *setToAdopt = NULL);
88
89 UChar32 nextCharLL();
90#ifdef RBBI_DEBUG
91 void printNodeStack(const char *title);
92#endif
93 RBBINode *pushNewNode(RBBINode::NodeType t);
94 void scanSet();
95
96
97 RBBIRuleBuilder *fRB; // The rule builder that we are part of.
98
99 int32_t fScanIndex; // Index of current character being processed
100 // in the rule input string.
101 int32_t fNextIndex; // Index of the next character, which
102 // is the first character not yet scanned.
103 UBool fQuoteMode; // Scan is in a 'quoted region'
104 int32_t fLineNum; // Line number in input file.
105 int32_t fCharNum; // Char position within the line.
106 UChar32 fLastChar; // Previous char, needed to count CR-LF
107 // as a single line, not two.
108
109 RBBIRuleChar fC; // Current char for parse state machine
110 // processing.
111 UnicodeString fVarName; // $variableName, valid when we've just
112 // scanned one.
113
114 RBBIRuleTableEl **fStateTable; // State Transition Table for RBBI Rule
115 // parsing. index by p[state][char-class]
116
117 uint16_t fStack[kStackSize]; // State stack, holds state pushes
118 int32_t fStackPtr; // and pops as specified in the state
119 // transition rules.
120
121 RBBINode *fNodeStack[kStackSize]; // Node stack, holds nodes created
122 // during the parse of a rule
123 int32_t fNodeStackPtr;
124
125
126 UBool fReverseRule; // True if the rule currently being scanned
127 // is a reverse direction rule (if it
128 // starts with a '!')
129
130 UBool fLookAheadRule; // True if the rule includes a '/'
131 // somewhere within it.
132
133 UBool fNoChainInRule; // True if the current rule starts with a '^'.
134
135 RBBISymbolTable *fSymbolTable; // symbol table, holds definitions of
136 // $variable symbols.
137
138 UHashtable *fSetTable; // UnicocodeSet hash table, holds indexes to
139 // the sets created while parsing rules.
140 // The key is the string used for creating
141 // the set.
142
143 UnicodeSet fRuleSets[10]; // Unicode Sets that are needed during
144 // the scanning of RBBI rules. The
145 // indicies for these are assigned by the
146 // perl script that builds the state tables.
147 // See rbbirpt.h.
148
149 int32_t fRuleNum; // Counts each rule as it is scanned.
150
151 int32_t fOptionStart; // Input index of start of a !!option
152 // keyword, while being scanned.
153
154 UnicodeSet *gRuleSet_rule_char;
155 UnicodeSet *gRuleSet_white_space;
156 UnicodeSet *gRuleSet_name_char;
157 UnicodeSet *gRuleSet_name_start_char;
158
159 RBBIRuleScanner(const RBBIRuleScanner &other); // forbid copying of this class
160 RBBIRuleScanner &operator=(const RBBIRuleScanner &other); // forbid copying of this class
161};
162
163U_NAMESPACE_END
164
165#endif
166