1// © 2016 and later: Unicode, Inc. and others.
2// License & terms of use: http://www.unicode.org/copyright.html
3/*
4 **********************************************************************
5 * Copyright (c) 2001-2011, International Business Machines
6 * Corporation and others. All Rights Reserved.
7 **********************************************************************
8 * Date Name Description
9 * 11/19/2001 aliu Creation.
10 **********************************************************************
11 */
12
13#ifndef ICU_UTIL_H
14#define ICU_UTIL_H
15
16#include "unicode/utypes.h"
17#include "unicode/uobject.h"
18#include "unicode/unistr.h"
19
20//--------------------------------------------------------------------
21// class ICU_Utility
22// i18n utility functions, scoped into the class ICU_Utility.
23//--------------------------------------------------------------------
24
25U_NAMESPACE_BEGIN
26
27class UnicodeMatcher;
28
29class U_COMMON_API ICU_Utility /* not : public UObject because all methods are static */ {
30 public:
31
32 /**
33 * Append a number to the given UnicodeString in the given radix.
34 * Standard digits '0'-'9' are used and letters 'A'-'Z' for
35 * radices 11 through 36.
36 * @param result the digits of the number are appended here
37 * @param n the number to be converted to digits; may be negative.
38 * If negative, a '-' is prepended to the digits.
39 * @param radix a radix from 2 to 36 inclusive.
40 * @param minDigits the minimum number of digits, not including
41 * any '-', to produce. Values less than 2 have no effect. One
42 * digit is always emitted regardless of this parameter.
43 * @return a reference to result
44 */
45 static UnicodeString& appendNumber(UnicodeString& result, int32_t n,
46 int32_t radix = 10,
47 int32_t minDigits = 1);
48
49 /** Returns a bogus UnicodeString by value. */
50 static inline UnicodeString makeBogusString() {
51 UnicodeString result;
52 result.setToBogus();
53 return result;
54 }
55
56 /**
57 * Return true if the character is NOT printable ASCII.
58 *
59 * This method should really be in UnicodeString (or similar). For
60 * now, we implement it here and share it with friend classes.
61 */
62 static UBool isUnprintable(UChar32 c);
63
64 /**
65 * Escape unprintable characters using \uxxxx notation for U+0000 to
66 * U+FFFF and \Uxxxxxxxx for U+10000 and above. If the character is
67 * printable ASCII, then do nothing and return FALSE. Otherwise,
68 * append the escaped notation and return TRUE.
69 */
70 static UBool escapeUnprintable(UnicodeString& result, UChar32 c);
71
72 /**
73 * Returns the index of a character, ignoring quoted text.
74 * For example, in the string "abc'hide'h", the 'h' in "hide" will not be
75 * found by a search for 'h'.
76 * @param text text to be searched
77 * @param start the beginning index, inclusive; <code>0 <= start
78 * <= limit</code>.
79 * @param limit the ending index, exclusive; <code>start <= limit
80 * <= text.length()</code>.
81 * @param c character to search for
82 * @return Offset of the first instance of c, or -1 if not found.
83 */
84//?FOR FUTURE USE. DISABLE FOR NOW for coverage reasons.
85// static int32_t quotedIndexOf(const UnicodeString& text,
86// int32_t start, int32_t limit,
87// UChar c);
88
89 /**
90 * Skip over a sequence of zero or more white space characters at pos.
91 * @param advance if true, advance pos to the first non-white-space
92 * character at or after pos, or str.length(), if there is none.
93 * Otherwise leave pos unchanged.
94 * @return the index of the first non-white-space character at or
95 * after pos, or str.length(), if there is none.
96 */
97 static int32_t skipWhitespace(const UnicodeString& str, int32_t& pos,
98 UBool advance = FALSE);
99
100 /**
101 * Skip over Pattern_White_Space in a Replaceable.
102 * Skipping may be done in the forward or
103 * reverse direction. In either case, the leftmost index will be
104 * inclusive, and the rightmost index will be exclusive. That is,
105 * given a range defined as [start, limit), the call
106 * skipWhitespace(text, start, limit) will advance start past leading
107 * whitespace, whereas the call skipWhitespace(text, limit, start),
108 * will back up limit past trailing whitespace.
109 * @param text the text to be analyzed
110 * @param pos either the start or limit of a range of 'text', to skip
111 * leading or trailing whitespace, respectively
112 * @param stop either the limit or start of a range of 'text', to skip
113 * leading or trailing whitespace, respectively
114 * @return the new start or limit, depending on what was passed in to
115 * 'pos'
116 */
117//?FOR FUTURE USE. DISABLE FOR NOW for coverage reasons.
118//? static int32_t skipWhitespace(const Replaceable& text,
119//? int32_t pos, int32_t stop);
120
121 /**
122 * Parse a single non-whitespace character 'ch', optionally
123 * preceded by whitespace.
124 * @param id the string to be parsed
125 * @param pos INPUT-OUTPUT parameter. On input, pos[0] is the
126 * offset of the first character to be parsed. On output, pos[0]
127 * is the index after the last parsed character. If the parse
128 * fails, pos[0] will be unchanged.
129 * @param ch the non-whitespace character to be parsed.
130 * @return true if 'ch' is seen preceded by zero or more
131 * whitespace characters.
132 */
133 static UBool parseChar(const UnicodeString& id, int32_t& pos, UChar ch);
134
135 /**
136 * Parse a pattern string starting at offset pos. Keywords are
137 * matched case-insensitively. Spaces may be skipped and may be
138 * optional or required. Integer values may be parsed, and if
139 * they are, they will be returned in the given array. If
140 * successful, the offset of the next non-space character is
141 * returned. On failure, -1 is returned.
142 * @param pattern must only contain lowercase characters, which
143 * will match their uppercase equivalents as well. A space
144 * character matches one or more required spaces. A '~' character
145 * matches zero or more optional spaces. A '#' character matches
146 * an integer and stores it in parsedInts, which the caller must
147 * ensure has enough capacity.
148 * @param parsedInts array to receive parsed integers. Caller
149 * must ensure that parsedInts.length is >= the number of '#'
150 * signs in 'pattern'.
151 * @return the position after the last character parsed, or -1 if
152 * the parse failed
153 */
154 static int32_t parsePattern(const UnicodeString& rule, int32_t pos, int32_t limit,
155 const UnicodeString& pattern, int32_t* parsedInts);
156
157 /**
158 * Parse a pattern string within the given Replaceable and a parsing
159 * pattern. Characters are matched literally and case-sensitively
160 * except for the following special characters:
161 *
162 * ~ zero or more Pattern_White_Space chars
163 *
164 * If end of pattern is reached with all matches along the way,
165 * pos is advanced to the first unparsed index and returned.
166 * Otherwise -1 is returned.
167 * @param pat pattern that controls parsing
168 * @param text text to be parsed, starting at index
169 * @param index offset to first character to parse
170 * @param limit offset after last character to parse
171 * @return index after last parsed character, or -1 on parse failure.
172 */
173 static int32_t parsePattern(const UnicodeString& pat,
174 const Replaceable& text,
175 int32_t index,
176 int32_t limit);
177
178 /**
179 * Parse an integer at pos, either of the form \d+ or of the form
180 * 0x[0-9A-Fa-f]+ or 0[0-7]+, that is, in standard decimal, hex,
181 * or octal format.
182 * @param pos INPUT-OUTPUT parameter. On input, the index of the first
183 * character to parse. On output, the index of the character after the
184 * last parsed character.
185 */
186 static int32_t parseInteger(const UnicodeString& rule, int32_t& pos, int32_t limit);
187
188 /**
189 * Parse an integer at pos using only ASCII digits.
190 * Base 10 only.
191 * @param pos INPUT-OUTPUT parameter. On input, the index of the first
192 * character to parse. On output, the index of the character after the
193 * last parsed character.
194 */
195 static int32_t parseAsciiInteger(const UnicodeString& str, int32_t& pos);
196
197 /**
198 * Parse a Unicode identifier from the given string at the given
199 * position. Return the identifier, or an empty string if there
200 * is no identifier.
201 * @param str the string to parse
202 * @param pos INPUT-OUPUT parameter. On INPUT, pos is the
203 * first character to examine. It must be less than str.length(),
204 * and it must not point to a whitespace character. That is, must
205 * have pos < str.length() and
206 * !UCharacter::isWhitespace(str.char32At(pos)). On
207 * OUTPUT, the position after the last parsed character.
208 * @return the Unicode identifier, or an empty string if there is
209 * no valid identifier at pos.
210 */
211 static UnicodeString parseUnicodeIdentifier(const UnicodeString& str, int32_t& pos);
212
213 /**
214 * Parse an unsigned 31-bit integer at the given offset. Use
215 * UCharacter.digit() to parse individual characters into digits.
216 * @param text the text to be parsed
217 * @param pos INPUT-OUTPUT parameter. On entry, pos is the
218 * offset within text at which to start parsing; it should point
219 * to a valid digit. On exit, pos is the offset after the last
220 * parsed character. If the parse failed, it will be unchanged on
221 * exit. Must be >= 0 on entry.
222 * @param radix the radix in which to parse; must be >= 2 and <=
223 * 36.
224 * @return a non-negative parsed number, or -1 upon parse failure.
225 * Parse fails if there are no digits, that is, if pos does not
226 * point to a valid digit on entry, or if the number to be parsed
227 * does not fit into a 31-bit unsigned integer.
228 */
229 static int32_t parseNumber(const UnicodeString& text,
230 int32_t& pos, int8_t radix);
231
232 static void appendToRule(UnicodeString& rule,
233 UChar32 c,
234 UBool isLiteral,
235 UBool escapeUnprintable,
236 UnicodeString& quoteBuf);
237
238 static void appendToRule(UnicodeString& rule,
239 const UnicodeString& text,
240 UBool isLiteral,
241 UBool escapeUnprintable,
242 UnicodeString& quoteBuf);
243
244 static void appendToRule(UnicodeString& rule,
245 const UnicodeMatcher* matcher,
246 UBool escapeUnprintable,
247 UnicodeString& quoteBuf);
248
249private:
250 // do not instantiate
251 ICU_Utility();
252};
253
254U_NAMESPACE_END
255
256#endif
257//eof
258