1 /*
2 **********************************************************************
3 * Copyright (c) 2003-2011, International Business Machines
4 * Corporation and others. All Rights Reserved.
5 **********************************************************************
6 * Author: Alan Liu
7 * Created: September 24 2003
8 * Since: ICU 2.8
9 **********************************************************************
10 */
11 #include "ruleiter.h"
12 #include "unicode/parsepos.h"
13 #include "unicode/symtable.h"
14 #include "unicode/unistr.h"
15 #include "unicode/utf16.h"
16 #include "patternprops.h"
17
18 /* \U87654321 or \ud800\udc00 */
19 #define MAX_U_NOTATION_LEN 12
20
21 U_NAMESPACE_BEGIN
22
RuleCharacterIterator(const UnicodeString & theText,const SymbolTable * theSym,ParsePosition & thePos)23 RuleCharacterIterator::RuleCharacterIterator(const UnicodeString& theText, const SymbolTable* theSym,
24 ParsePosition& thePos) :
25 text(theText),
26 pos(thePos),
27 sym(theSym),
28 buf(0),
29 bufPos(0)
30 {}
31
atEnd() const32 UBool RuleCharacterIterator::atEnd() const {
33 return buf == 0 && pos.getIndex() == text.length();
34 }
35
next(int32_t options,UBool & isEscaped,UErrorCode & ec)36 UChar32 RuleCharacterIterator::next(int32_t options, UBool& isEscaped, UErrorCode& ec) {
37 if (U_FAILURE(ec)) return DONE;
38
39 UChar32 c = DONE;
40 isEscaped = FALSE;
41
42 for (;;) {
43 c = _current();
44 _advance(U16_LENGTH(c));
45
46 if (c == SymbolTable::SYMBOL_REF && buf == 0 &&
47 (options & PARSE_VARIABLES) != 0 && sym != 0) {
48 UnicodeString name = sym->parseReference(text, pos, text.length());
49 // If name is empty there was an isolated SYMBOL_REF;
50 // return it. Caller must be prepared for this.
51 if (name.length() == 0) {
52 break;
53 }
54 bufPos = 0;
55 buf = sym->lookup(name);
56 if (buf == 0) {
57 ec = U_UNDEFINED_VARIABLE;
58 return DONE;
59 }
60 // Handle empty variable value
61 if (buf->length() == 0) {
62 buf = 0;
63 }
64 continue;
65 }
66
67 if ((options & SKIP_WHITESPACE) != 0 && PatternProps::isWhiteSpace(c)) {
68 continue;
69 }
70
71 if (c == 0x5C /*'\\'*/ && (options & PARSE_ESCAPES) != 0) {
72 UnicodeString tempEscape;
73 int32_t offset = 0;
74 c = lookahead(tempEscape, MAX_U_NOTATION_LEN).unescapeAt(offset);
75 jumpahead(offset);
76 isEscaped = TRUE;
77 if (c < 0) {
78 ec = U_MALFORMED_UNICODE_ESCAPE;
79 return DONE;
80 }
81 }
82
83 break;
84 }
85
86 return c;
87 }
88
getPos(RuleCharacterIterator::Pos & p) const89 void RuleCharacterIterator::getPos(RuleCharacterIterator::Pos& p) const {
90 p.buf = buf;
91 p.pos = pos.getIndex();
92 p.bufPos = bufPos;
93 }
94
setPos(const RuleCharacterIterator::Pos & p)95 void RuleCharacterIterator::setPos(const RuleCharacterIterator::Pos& p) {
96 buf = p.buf;
97 pos.setIndex(p.pos);
98 bufPos = p.bufPos;
99 }
100
skipIgnored(int32_t options)101 void RuleCharacterIterator::skipIgnored(int32_t options) {
102 if ((options & SKIP_WHITESPACE) != 0) {
103 for (;;) {
104 UChar32 a = _current();
105 if (!PatternProps::isWhiteSpace(a)) break;
106 _advance(U16_LENGTH(a));
107 }
108 }
109 }
110
lookahead(UnicodeString & result,int32_t maxLookAhead) const111 UnicodeString& RuleCharacterIterator::lookahead(UnicodeString& result, int32_t maxLookAhead) const {
112 if (maxLookAhead < 0) {
113 maxLookAhead = 0x7FFFFFFF;
114 }
115 if (buf != 0) {
116 buf->extract(bufPos, maxLookAhead, result);
117 } else {
118 text.extract(pos.getIndex(), maxLookAhead, result);
119 }
120 return result;
121 }
122
jumpahead(int32_t count)123 void RuleCharacterIterator::jumpahead(int32_t count) {
124 _advance(count);
125 }
126
127 /*
128 UnicodeString& RuleCharacterIterator::toString(UnicodeString& result) const {
129 int32_t b = pos.getIndex();
130 text.extract(0, b, result);
131 return result.append((UChar) 0x7C).append(text, b, 0x7FFFFFFF); // Insert '|' at index
132 }
133 */
134
_current() const135 UChar32 RuleCharacterIterator::_current() const {
136 if (buf != 0) {
137 return buf->char32At(bufPos);
138 } else {
139 int i = pos.getIndex();
140 return (i < text.length()) ? text.char32At(i) : (UChar32)DONE;
141 }
142 }
143
_advance(int32_t count)144 void RuleCharacterIterator::_advance(int32_t count) {
145 if (buf != 0) {
146 bufPos += count;
147 if (bufPos == buf->length()) {
148 buf = 0;
149 }
150 } else {
151 pos.setIndex(pos.getIndex() + count);
152 if (pos.getIndex() > text.length()) {
153 pos.setIndex(text.length());
154 }
155 }
156 }
157
158 U_NAMESPACE_END
159
160 //eof
161