double-conversion-string-to-double.h (11365B)
1 // © 2018 and later: Unicode, Inc. and others. 2 // License & terms of use: http://www.unicode.org/copyright.html 3 // 4 // From the double-conversion library. Original license: 5 // 6 // Copyright 2012 the V8 project authors. All rights reserved. 7 // Redistribution and use in source and binary forms, with or without 8 // modification, are permitted provided that the following conditions are 9 // met: 10 // 11 // * Redistributions of source code must retain the above copyright 12 // notice, this list of conditions and the following disclaimer. 13 // * Redistributions in binary form must reproduce the above 14 // copyright notice, this list of conditions and the following 15 // disclaimer in the documentation and/or other materials provided 16 // with the distribution. 17 // * Neither the name of Google Inc. nor the names of its 18 // contributors may be used to endorse or promote products derived 19 // from this software without specific prior written permission. 20 // 21 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 24 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 25 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 26 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 27 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 31 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 33 // ICU PATCH: ifdef around UCONFIG_NO_FORMATTING 34 #include "unicode/utypes.h" 35 #if !UCONFIG_NO_FORMATTING 36 37 #ifndef DOUBLE_CONVERSION_STRING_TO_DOUBLE_H_ 38 #define DOUBLE_CONVERSION_STRING_TO_DOUBLE_H_ 39 40 // ICU PATCH: Customize header file paths for ICU. 41 42 #include "double-conversion-utils.h" 43 44 // ICU PATCH: Wrap in ICU namespace 45 U_NAMESPACE_BEGIN 46 47 namespace double_conversion { 48 49 class StringToDoubleConverter { 50 public: 51 // Enumeration for allowing octals and ignoring junk when converting 52 // strings to numbers. 53 enum Flags { 54 NO_FLAGS = 0, 55 ALLOW_HEX = 1, 56 ALLOW_OCTALS = 2, 57 ALLOW_TRAILING_JUNK = 4, 58 ALLOW_LEADING_SPACES = 8, 59 ALLOW_TRAILING_SPACES = 16, 60 ALLOW_SPACES_AFTER_SIGN = 32, 61 ALLOW_CASE_INSENSITIVITY = 64, 62 ALLOW_CASE_INSENSIBILITY = 64, // Deprecated 63 ALLOW_HEX_FLOATS = 128, 64 }; 65 66 static const uc16 kNoSeparator = '\0'; 67 68 // Flags should be a bit-or combination of the possible Flags-enum. 69 // - NO_FLAGS: no special flags. 70 // - ALLOW_HEX: recognizes the prefix "0x". Hex numbers may only be integers. 71 // Ex: StringToDouble("0x1234") -> 4660.0 72 // In StringToDouble("0x1234.56") the characters ".56" are trailing 73 // junk. The result of the call is hence dependent on 74 // the ALLOW_TRAILING_JUNK flag and/or the junk value. 75 // With this flag "0x" is a junk-string. Even with ALLOW_TRAILING_JUNK, 76 // the string will not be parsed as "0" followed by junk. 77 // 78 // - ALLOW_OCTALS: recognizes the prefix "0" for octals: 79 // If a sequence of octal digits starts with '0', then the number is 80 // read as octal integer. Octal numbers may only be integers. 81 // Ex: StringToDouble("01234") -> 668.0 82 // StringToDouble("012349") -> 12349.0 // Not a sequence of octal 83 // // digits. 84 // In StringToDouble("01234.56") the characters ".56" are trailing 85 // junk. The result of the call is hence dependent on 86 // the ALLOW_TRAILING_JUNK flag and/or the junk value. 87 // In StringToDouble("01234e56") the characters "e56" are trailing 88 // junk, too. 89 // - ALLOW_TRAILING_JUNK: ignore trailing characters that are not part of 90 // a double literal. 91 // - ALLOW_LEADING_SPACES: skip over leading whitespace, including spaces, 92 // new-lines, and tabs. 93 // - ALLOW_TRAILING_SPACES: ignore trailing whitespace. 94 // - ALLOW_SPACES_AFTER_SIGN: ignore whitespace after the sign. 95 // Ex: StringToDouble("- 123.2") -> -123.2. 96 // StringToDouble("+ 123.2") -> 123.2 97 // - ALLOW_CASE_INSENSITIVITY: ignore case of characters for special values: 98 // infinity and nan. 99 // - ALLOW_HEX_FLOATS: allows hexadecimal float literals. 100 // This *must* start with "0x" and separate the exponent with "p". 101 // Examples: 0x1.2p3 == 9.0 102 // 0x10.1p0 == 16.0625 103 // ALLOW_HEX and ALLOW_HEX_FLOATS are indented. 104 // 105 // empty_string_value is returned when an empty string is given as input. 106 // If ALLOW_LEADING_SPACES or ALLOW_TRAILING_SPACES are set, then a string 107 // containing only spaces is converted to the 'empty_string_value', too. 108 // 109 // junk_string_value is returned when 110 // a) ALLOW_TRAILING_JUNK is not set, and a junk character (a character not 111 // part of a double-literal) is found. 112 // b) ALLOW_TRAILING_JUNK is set, but the string does not start with a 113 // double literal. 114 // 115 // infinity_symbol and nan_symbol are strings that are used to detect 116 // inputs that represent infinity and NaN. They can be null, in which case 117 // they are ignored. 118 // The conversion routine first reads any possible signs. Then it compares the 119 // following character of the input-string with the first character of 120 // the infinity, and nan-symbol. If either matches, the function assumes, that 121 // a match has been found, and expects the following input characters to match 122 // the remaining characters of the special-value symbol. 123 // This means that the following restrictions apply to special-value symbols: 124 // - they must not start with signs ('+', or '-'), 125 // - they must not have the same first character. 126 // - they must not start with digits. 127 // 128 // If the separator character is not kNoSeparator, then that specific 129 // character is ignored when in between two valid digits of the significant. 130 // It is not allowed to appear in the exponent. 131 // It is not allowed to lead or trail the number. 132 // It is not allowed to appear twice next to each other. 133 // 134 // Examples: 135 // flags = ALLOW_HEX | ALLOW_TRAILING_JUNK, 136 // empty_string_value = 0.0, 137 // junk_string_value = NaN, 138 // infinity_symbol = "infinity", 139 // nan_symbol = "nan": 140 // StringToDouble("0x1234") -> 4660.0. 141 // StringToDouble("0x1234K") -> 4660.0. 142 // StringToDouble("") -> 0.0 // empty_string_value. 143 // StringToDouble(" ") -> NaN // junk_string_value. 144 // StringToDouble(" 1") -> NaN // junk_string_value. 145 // StringToDouble("0x") -> NaN // junk_string_value. 146 // StringToDouble("-123.45") -> -123.45. 147 // StringToDouble("--123.45") -> NaN // junk_string_value. 148 // StringToDouble("123e45") -> 123e45. 149 // StringToDouble("123E45") -> 123e45. 150 // StringToDouble("123e+45") -> 123e45. 151 // StringToDouble("123E-45") -> 123e-45. 152 // StringToDouble("123e") -> 123.0 // trailing junk ignored. 153 // StringToDouble("123e-") -> 123.0 // trailing junk ignored. 154 // StringToDouble("+NaN") -> NaN // NaN string literal. 155 // StringToDouble("-infinity") -> -inf. // infinity literal. 156 // StringToDouble("Infinity") -> NaN // junk_string_value. 157 // 158 // flags = ALLOW_OCTAL | ALLOW_LEADING_SPACES, 159 // empty_string_value = 0.0, 160 // junk_string_value = NaN, 161 // infinity_symbol = nullptr, 162 // nan_symbol = nullptr: 163 // StringToDouble("0x1234") -> NaN // junk_string_value. 164 // StringToDouble("01234") -> 668.0. 165 // StringToDouble("") -> 0.0 // empty_string_value. 166 // StringToDouble(" ") -> 0.0 // empty_string_value. 167 // StringToDouble(" 1") -> 1.0 168 // StringToDouble("0x") -> NaN // junk_string_value. 169 // StringToDouble("0123e45") -> NaN // junk_string_value. 170 // StringToDouble("01239E45") -> 1239e45. 171 // StringToDouble("-infinity") -> NaN // junk_string_value. 172 // StringToDouble("NaN") -> NaN // junk_string_value. 173 // 174 // flags = NO_FLAGS, 175 // separator = ' ': 176 // StringToDouble("1 2 3 4") -> 1234.0 177 // StringToDouble("1 2") -> NaN // junk_string_value 178 // StringToDouble("1 000 000.0") -> 1000000.0 179 // StringToDouble("1.000 000") -> 1.0 180 // StringToDouble("1.0e1 000") -> NaN // junk_string_value 181 StringToDoubleConverter(int flags, 182 double empty_string_value, 183 double junk_string_value, 184 const char* infinity_symbol, 185 const char* nan_symbol, 186 uc16 separator = kNoSeparator) 187 : flags_(flags), 188 empty_string_value_(empty_string_value), 189 junk_string_value_(junk_string_value), 190 infinity_symbol_(infinity_symbol), 191 nan_symbol_(nan_symbol), 192 separator_(separator) { 193 } 194 195 // Performs the conversion. 196 // The output parameter 'processed_characters_count' is set to the number 197 // of characters that have been processed to read the number. 198 // Spaces than are processed with ALLOW_{LEADING|TRAILING}_SPACES are included 199 // in the 'processed_characters_count'. Trailing junk is never included. 200 double StringToDouble(const char* buffer, 201 int length, 202 int* processed_characters_count) const; 203 204 // Same as StringToDouble above but for 16 bit characters. 205 double StringToDouble(const uc16* buffer, 206 int length, 207 int* processed_characters_count) const; 208 209 // Same as StringToDouble but reads a float. 210 // Note that this is not equivalent to static_cast<float>(StringToDouble(...)) 211 // due to potential double-rounding. 212 float StringToFloat(const char* buffer, 213 int length, 214 int* processed_characters_count) const; 215 216 // Same as StringToFloat above but for 16 bit characters. 217 float StringToFloat(const uc16* buffer, 218 int length, 219 int* processed_characters_count) const; 220 221 // Same as StringToDouble for T = double, and StringToFloat for T = float. 222 template <typename T> 223 T StringTo(const char* buffer, 224 int length, 225 int* processed_characters_count) const; 226 227 // Same as StringTo above but for 16 bit characters. 228 template <typename T> 229 T StringTo(const uc16* buffer, 230 int length, 231 int* processed_characters_count) const; 232 233 private: 234 const int flags_; 235 const double empty_string_value_; 236 const double junk_string_value_; 237 const char* const infinity_symbol_; 238 const char* const nan_symbol_; 239 const uc16 separator_; 240 241 template <class Iterator> 242 double StringToIeee(Iterator start_pointer, 243 int length, 244 bool read_as_double, 245 int* processed_characters_count) const; 246 247 DOUBLE_CONVERSION_DISALLOW_IMPLICIT_CONSTRUCTORS(StringToDoubleConverter); 248 }; 249 250 } // namespace double_conversion 251 252 // ICU PATCH: Close ICU namespace 253 U_NAMESPACE_END 254 255 #endif // DOUBLE_CONVERSION_STRING_TO_DOUBLE_H_ 256 #endif // ICU PATCH: close #if !UCONFIG_NO_FORMATTING