1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4 **********************************************************************
5 * Copyright (c) 2003-2011, International Business Machines
6 * Corporation and others. All Rights Reserved.
7 **********************************************************************
8 * Author: Alan Liu
9 * Created: September 24 2003
10 * Since: ICU 2.8
11 **********************************************************************
12 */
13 #include "ruleiter.h"
14 #include "unicode/parsepos.h"
15 #include "unicode/symtable.h"
16 #include "unicode/unistr.h"
17 #include "unicode/utf16.h"
18 #include "patternprops.h"
19
20 /* \U87654321 or \ud800\udc00 */
21 #define MAX_U_NOTATION_LEN 12
22
23 U_NAMESPACE_BEGIN
24
RuleCharacterIterator(const UnicodeString & theText,const SymbolTable * theSym,ParsePosition & thePos)25 RuleCharacterIterator::RuleCharacterIterator(const UnicodeString& theText, const SymbolTable* theSym,
26 ParsePosition& thePos) :
27 text(theText),
28 pos(thePos),
29 sym(theSym),
30 buf(0),
31 bufPos(0)
32 {}
33
atEnd() const34 UBool RuleCharacterIterator::atEnd() const {
35 return buf == 0 && pos.getIndex() == text.length();
36 }
37
next(int32_t options,UBool & isEscaped,UErrorCode & ec)38 UChar32 RuleCharacterIterator::next(int32_t options, UBool& isEscaped, UErrorCode& ec) {
39 if (U_FAILURE(ec)) return DONE;
40
41 UChar32 c = DONE;
42 isEscaped = FALSE;
43
44 for (;;) {
45 c = _current();
46 _advance(U16_LENGTH(c));
47
48 if (c == SymbolTable::SYMBOL_REF && buf == 0 &&
49 (options & PARSE_VARIABLES) != 0 && sym != 0) {
50 UnicodeString name = sym->parseReference(text, pos, text.length());
51 // If name is empty there was an isolated SYMBOL_REF;
52 // return it. Caller must be prepared for this.
53 if (name.length() == 0) {
54 break;
55 }
56 bufPos = 0;
57 buf = sym->lookup(name);
58 if (buf == 0) {
59 ec = U_UNDEFINED_VARIABLE;
60 return DONE;
61 }
62 // Handle empty variable value
63 if (buf->length() == 0) {
64 buf = 0;
65 }
66 continue;
67 }
68
69 if ((options & SKIP_WHITESPACE) != 0 && PatternProps::isWhiteSpace(c)) {
70 continue;
71 }
72
73 if (c == 0x5C /*'\\'*/ && (options & PARSE_ESCAPES) != 0) {
74 UnicodeString tempEscape;
75 int32_t offset = 0;
76 c = lookahead(tempEscape, MAX_U_NOTATION_LEN).unescapeAt(offset);
77 jumpahead(offset);
78 isEscaped = TRUE;
79 if (c < 0) {
80 ec = U_MALFORMED_UNICODE_ESCAPE;
81 return DONE;
82 }
83 }
84
85 break;
86 }
87
88 return c;
89 }
90
getPos(RuleCharacterIterator::Pos & p) const91 void RuleCharacterIterator::getPos(RuleCharacterIterator::Pos& p) const {
92 p.buf = buf;
93 p.pos = pos.getIndex();
94 p.bufPos = bufPos;
95 }
96
setPos(const RuleCharacterIterator::Pos & p)97 void RuleCharacterIterator::setPos(const RuleCharacterIterator::Pos& p) {
98 buf = p.buf;
99 pos.setIndex(p.pos);
100 bufPos = p.bufPos;
101 }
102
skipIgnored(int32_t options)103 void RuleCharacterIterator::skipIgnored(int32_t options) {
104 if ((options & SKIP_WHITESPACE) != 0) {
105 for (;;) {
106 UChar32 a = _current();
107 if (!PatternProps::isWhiteSpace(a)) break;
108 _advance(U16_LENGTH(a));
109 }
110 }
111 }
112
lookahead(UnicodeString & result,int32_t maxLookAhead) const113 UnicodeString& RuleCharacterIterator::lookahead(UnicodeString& result, int32_t maxLookAhead) const {
114 if (maxLookAhead < 0) {
115 maxLookAhead = 0x7FFFFFFF;
116 }
117 if (buf != 0) {
118 buf->extract(bufPos, maxLookAhead, result);
119 } else {
120 text.extract(pos.getIndex(), maxLookAhead, result);
121 }
122 return result;
123 }
124
jumpahead(int32_t count)125 void RuleCharacterIterator::jumpahead(int32_t count) {
126 _advance(count);
127 }
128
129 /*
130 UnicodeString& RuleCharacterIterator::toString(UnicodeString& result) const {
131 int32_t b = pos.getIndex();
132 text.extract(0, b, result);
133 return result.append((UChar) 0x7C).append(text, b, 0x7FFFFFFF); // Insert '|' at index
134 }
135 */
136
_current() const137 UChar32 RuleCharacterIterator::_current() const {
138 if (buf != 0) {
139 return buf->char32At(bufPos);
140 } else {
141 int i = pos.getIndex();
142 return (i < text.length()) ? text.char32At(i) : (UChar32)DONE;
143 }
144 }
145
_advance(int32_t count)146 void RuleCharacterIterator::_advance(int32_t count) {
147 if (buf != 0) {
148 bufPos += count;
149 if (bufPos == buf->length()) {
150 buf = 0;
151 }
152 } else {
153 pos.setIndex(pos.getIndex() + count);
154 if (pos.getIndex() > text.length()) {
155 pos.setIndex(text.length());
156 }
157 }
158 }
159
160 U_NAMESPACE_END
161
162 //eof
163