1 /* 2 ********************************************************************** 3 * Copyright (c) 2001-2006, International Business Machines 4 * Corporation and others. All Rights Reserved. 5 ********************************************************************** 6 * Date Name Description 7 * 11/19/2001 aliu Creation. 8 ********************************************************************** 9 */ 10 11 #include "util.h" 12 #include "unicode/uchar.h" 13 14 U_NAMESPACE_BEGIN 15 16 /** 17 * Parse an integer at pos, either of the form \d+ or of the form 18 * 0x[0-9A-Fa-f]+ or 0[0-7]+, that is, in standard decimal, hex, 19 * or octal format. 20 * @param pos INPUT-OUTPUT parameter. On input, the first 21 * character to parse. On output, the character after the last 22 * parsed character. 23 */ 24 int32_t ICU_Utility::parseInteger(const UnicodeString& rule, int32_t& pos, int32_t limit) { 25 int32_t count = 0; 26 int32_t value = 0; 27 int32_t p = pos; 28 int8_t radix = 10; 29 30 if (p < limit && rule.charAt(p) == 48 /*0*/) { 31 if (p+1 < limit && (rule.charAt(p+1) == 0x78 /*x*/ || rule.charAt(p+1) == 0x58 /*X*/)) { 32 p += 2; 33 radix = 16; 34 } 35 else { 36 p++; 37 count = 1; 38 radix = 8; 39 } 40 } 41 42 while (p < limit) { 43 int32_t d = u_digit(rule.charAt(p++), radix); 44 if (d < 0) { 45 --p; 46 break; 47 } 48 ++count; 49 int32_t v = (value * radix) + d; 50 if (v <= value) { 51 // If there are too many input digits, at some point 52 // the value will go negative, e.g., if we have seen 53 // "0x8000000" already and there is another '0', when 54 // we parse the next 0 the value will go negative. 55 return 0; 56 } 57 value = v; 58 } 59 if (count > 0) { 60 pos = p; 61 } 62 return value; 63 } 64 65 /** 66 * Parse a pattern string starting at offset pos. Keywords are 67 * matched case-insensitively. Spaces may be skipped and may be 68 * optional or required. Integer values may be parsed, and if 69 * they are, they will be returned in the given array. If 70 * successful, the offset of the next non-space character is 71 * returned. On failure, -1 is returned. 72 * @param pattern must only contain lowercase characters, which 73 * will match their uppercase equivalents as well. A space 74 * character matches one or more required spaces. A '~' character 75 * matches zero or more optional spaces. A '#' character matches 76 * an integer and stores it in parsedInts, which the caller must 77 * ensure has enough capacity. 78 * @param parsedInts array to receive parsed integers. Caller 79 * must ensure that parsedInts.length is >= the number of '#' 80 * signs in 'pattern'. 81 * @return the position after the last character parsed, or -1 if 82 * the parse failed 83 */ 84 int32_t ICU_Utility::parsePattern(const UnicodeString& rule, int32_t pos, int32_t limit, 85 const UnicodeString& pattern, int32_t* parsedInts) { 86 // TODO Update this to handle surrogates 87 int32_t p; 88 int32_t intCount = 0; // number of integers parsed 89 for (int32_t i=0; i<pattern.length(); ++i) { 90 UChar cpat = pattern.charAt(i); 91 UChar c; 92 switch (cpat) { 93 case 32 /*' '*/: 94 if (pos >= limit) { 95 return -1; 96 } 97 c = rule.charAt(pos++); 98 if (!uprv_isRuleWhiteSpace(c)) { 99 return -1; 100 } 101 // FALL THROUGH to skipWhitespace 102 case 126 /*'~'*/: 103 pos = skipWhitespace(rule, pos); 104 break; 105 case 35 /*'#'*/: 106 p = pos; 107 parsedInts[intCount++] = parseInteger(rule, p, limit); 108 if (p == pos) { 109 // Syntax error; failed to parse integer 110 return -1; 111 } 112 pos = p; 113 break; 114 default: 115 if (pos >= limit) { 116 return -1; 117 } 118 c = (UChar) u_tolower(rule.charAt(pos++)); 119 if (c != cpat) { 120 return -1; 121 } 122 break; 123 } 124 } 125 return pos; 126 } 127 128 /** 129 * Parse a Unicode identifier from the given string at the given 130 * position. Return the identifier, or an empty string if there 131 * is no identifier. 132 * @param str the string to parse 133 * @param pos INPUT-OUPUT parameter. On INPUT, pos is the 134 * first character to examine. It must be less than str.length(), 135 * and it must not point to a whitespace character. That is, must 136 * have pos < str.length() and 137 * !uprv_isRuleWhiteSpace(str.char32At(pos)). On 138 * OUTPUT, the position after the last parsed character. 139 * @return the Unicode identifier, or an empty string if there is 140 * no valid identifier at pos. 141 */ 142 UnicodeString ICU_Utility::parseUnicodeIdentifier(const UnicodeString& str, int32_t& pos) { 143 // assert(pos < str.length()); 144 // assert(!uprv_isRuleWhiteSpace(str.char32At(pos))); 145 UnicodeString buf; 146 int p = pos; 147 while (p < str.length()) { 148 UChar32 ch = str.char32At(p); 149 if (buf.length() == 0) { 150 if (u_isIDStart(ch)) { 151 buf.append(ch); 152 } else { 153 buf.truncate(0); 154 return buf; 155 } 156 } else { 157 if (u_isIDPart(ch)) { 158 buf.append(ch); 159 } else { 160 break; 161 } 162 } 163 p += UTF_CHAR_LENGTH(ch); 164 } 165 pos = p; 166 return buf; 167 } 168 169 /** 170 * Parse an unsigned 31-bit integer at the given offset. Use 171 * UCharacter.digit() to parse individual characters into digits. 172 * @param text the text to be parsed 173 * @param pos INPUT-OUTPUT parameter. On entry, pos[0] is the 174 * offset within text at which to start parsing; it should point 175 * to a valid digit. On exit, pos[0] is the offset after the last 176 * parsed character. If the parse failed, it will be unchanged on 177 * exit. Must be >= 0 on entry. 178 * @param radix the radix in which to parse; must be >= 2 and <= 179 * 36. 180 * @return a non-negative parsed number, or -1 upon parse failure. 181 * Parse fails if there are no digits, that is, if pos[0] does not 182 * point to a valid digit on entry, or if the number to be parsed 183 * does not fit into a 31-bit unsigned integer. 184 */ 185 int32_t ICU_Utility::parseNumber(const UnicodeString& text, 186 int32_t& pos, int8_t radix) { 187 // assert(pos[0] >= 0); 188 // assert(radix >= 2); 189 // assert(radix <= 36); 190 int32_t n = 0; 191 int32_t p = pos; 192 while (p < text.length()) { 193 UChar32 ch = text.char32At(p); 194 int32_t d = u_digit(ch, radix); 195 if (d < 0) { 196 break; 197 } 198 n = radix*n + d; 199 // ASSUME that when a 32-bit integer overflows it becomes 200 // negative. E.g., 214748364 * 10 + 8 => negative value. 201 if (n < 0) { 202 return -1; 203 } 204 ++p; 205 } 206 if (p == pos) { 207 return -1; 208 } 209 pos = p; 210 return n; 211 } 212 213 U_NAMESPACE_END 214 215
