Victor Chang | 7322950 | 2020-09-17 13:39:19 +0100 | [diff] [blame] | 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 indendent. |
| 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 = NULL, |
| 162 | // nan_symbol = NULL: |
| 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 | private: |
| 222 | const int flags_; |
| 223 | const double empty_string_value_; |
| 224 | const double junk_string_value_; |
| 225 | const char* const infinity_symbol_; |
| 226 | const char* const nan_symbol_; |
| 227 | const uc16 separator_; |
| 228 | |
| 229 | template <class Iterator> |
| 230 | double StringToIeee(Iterator start_pointer, |
| 231 | int length, |
| 232 | bool read_as_double, |
| 233 | int* processed_characters_count) const; |
| 234 | |
| 235 | DOUBLE_CONVERSION_DISALLOW_IMPLICIT_CONSTRUCTORS(StringToDoubleConverter); |
| 236 | }; |
| 237 | |
| 238 | } // namespace double_conversion |
| 239 | |
| 240 | // ICU PATCH: Close ICU namespace |
| 241 | U_NAMESPACE_END |
| 242 | |
| 243 | #endif // DOUBLE_CONVERSION_STRING_TO_DOUBLE_H_ |
| 244 | #endif // ICU PATCH: close #if !UCONFIG_NO_FORMATTING |