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