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27
28#ifndef DOUBLE_CONVERSION_DOUBLE_CONVERSION_H_
29#define DOUBLE_CONVERSION_DOUBLE_CONVERSION_H_
30
31#include <double-conversion/utils.h>
32
33namespace double_conversion {
34
35class DoubleToStringConverter {
36 public:
37 // When calling ToFixed with a double > 10^kMaxFixedDigitsBeforePoint
38 // or a requested_digits parameter > kMaxFixedDigitsAfterPoint then the
39 // function returns false.
40 static const int kMaxFixedDigitsBeforePoint = 60;
41 static const int kMaxFixedDigitsAfterPoint = 60;
42
43 // When calling ToExponential with a requested_digits
44 // parameter > kMaxExponentialDigits then the function returns false.
45 static const int kMaxExponentialDigits = 120;
46
47 // When calling ToPrecision with a requested_digits
48 // parameter < kMinPrecisionDigits or requested_digits > kMaxPrecisionDigits
49 // then the function returns false.
50 static const int kMinPrecisionDigits = 1;
51 static const int kMaxPrecisionDigits = 120;
52
53 enum Flags {
54 NO_FLAGS = 0,
55 EMIT_POSITIVE_EXPONENT_SIGN = 1,
56 EMIT_TRAILING_DECIMAL_POINT = 2,
57 EMIT_TRAILING_ZERO_AFTER_POINT = 4,
58 UNIQUE_ZERO = 8
59 };
60
61 // Flags should be a bit-or combination of the possible Flags-enum.
62 // - NO_FLAGS: no special flags.
63 // - EMIT_POSITIVE_EXPONENT_SIGN: when the number is converted into exponent
64 // form, emits a '+' for positive exponents. Example: 1.2e+2.
65 // - EMIT_TRAILING_DECIMAL_POINT: when the input number is an integer and is
66 // converted into decimal format then a trailing decimal point is appended.
67 // Example: 2345.0 is converted to "2345.".
68 // - EMIT_TRAILING_ZERO_AFTER_POINT: in addition to a trailing decimal point
69 // emits a trailing '0'-character. This flag requires the
70 // EXMIT_TRAILING_DECIMAL_POINT flag.
71 // Example: 2345.0 is converted to "2345.0".
72 // - UNIQUE_ZERO: "-0.0" is converted to "0.0".
73 //
74 // Infinity symbol and nan_symbol provide the string representation for these
75 // special values. If the string is NULL and the special value is encountered
76 // then the conversion functions return false.
77 //
78 // The exponent_character is used in exponential representations. It is
79 // usually 'e' or 'E'.
80 //
81 // When converting to the shortest representation the converter will
82 // represent input numbers in decimal format if they are in the interval
83 // [10^decimal_in_shortest_low; 10^decimal_in_shortest_high[
84 // (lower boundary included, greater boundary excluded).
85 // Example: with decimal_in_shortest_low = -6 and
86 // decimal_in_shortest_high = 21:
87 // ToShortest(0.000001) -> "0.000001"
88 // ToShortest(0.0000001) -> "1e-7"
89 // ToShortest(111111111111111111111.0) -> "111111111111111110000"
90 // ToShortest(100000000000000000000.0) -> "100000000000000000000"
91 // ToShortest(1111111111111111111111.0) -> "1.1111111111111111e+21"
92 //
93 // When converting to precision mode the converter may add
94 // max_leading_padding_zeroes before returning the number in exponential
95 // format.
96 // Example with max_leading_padding_zeroes_in_precision_mode = 6.
97 // ToPrecision(0.0000012345, 2) -> "0.0000012"
98 // ToPrecision(0.00000012345, 2) -> "1.2e-7"
99 // Similarily the converter may add up to
100 // max_trailing_padding_zeroes_in_precision_mode in precision mode to avoid
101 // returning an exponential representation. A zero added by the
102 // EMIT_TRAILING_ZERO_AFTER_POINT flag is counted for this limit.
103 // Examples for max_trailing_padding_zeroes_in_precision_mode = 1:
104 // ToPrecision(230.0, 2) -> "230"
105 // ToPrecision(230.0, 2) -> "230." with EMIT_TRAILING_DECIMAL_POINT.
106 // ToPrecision(230.0, 2) -> "2.3e2" with EMIT_TRAILING_ZERO_AFTER_POINT.
107 DoubleToStringConverter(int flags,
108 const char* infinity_symbol,
109 const char* nan_symbol,
110 char exponent_character,
111 int decimal_in_shortest_low,
112 int decimal_in_shortest_high,
113 int max_leading_padding_zeroes_in_precision_mode,
114 int max_trailing_padding_zeroes_in_precision_mode)
115 : flags_(flags),
116 infinity_symbol_(infinity_symbol),
117 nan_symbol_(nan_symbol),
118 exponent_character_(exponent_character),
119 decimal_in_shortest_low_(decimal_in_shortest_low),
120 decimal_in_shortest_high_(decimal_in_shortest_high),
121 max_leading_padding_zeroes_in_precision_mode_(
122 max_leading_padding_zeroes_in_precision_mode),
123 max_trailing_padding_zeroes_in_precision_mode_(
124 max_trailing_padding_zeroes_in_precision_mode) {
125 // When 'trailing zero after the point' is set, then 'trailing point'
126 // must be set too.
127 ASSERT(((flags & EMIT_TRAILING_DECIMAL_POINT) != 0) ||
128 !((flags & EMIT_TRAILING_ZERO_AFTER_POINT) != 0));
129 }
130
131 // Returns a converter following the EcmaScript specification.
132 static const DoubleToStringConverter& EcmaScriptConverter();
133
134 // Computes the shortest string of digits that correctly represent the input
135 // number. Depending on decimal_in_shortest_low and decimal_in_shortest_high
136 // (see constructor) it then either returns a decimal representation, or an
137 // exponential representation.
138 // Example with decimal_in_shortest_low = -6,
139 // decimal_in_shortest_high = 21,
140 // EMIT_POSITIVE_EXPONENT_SIGN activated, and
141 // EMIT_TRAILING_DECIMAL_POINT deactived:
142 // ToShortest(0.000001) -> "0.000001"
143 // ToShortest(0.0000001) -> "1e-7"
144 // ToShortest(111111111111111111111.0) -> "111111111111111110000"
145 // ToShortest(100000000000000000000.0) -> "100000000000000000000"
146 // ToShortest(1111111111111111111111.0) -> "1.1111111111111111e+21"
147 //
148 // Note: the conversion may round the output if the returned string
149 // is accurate enough to uniquely identify the input-number.
150 // For example the most precise representation of the double 9e59 equals
151 // "899999999999999918767229449717619953810131273674690656206848", but
152 // the converter will return the shorter (but still correct) "9e59".
153 //
154 // Returns true if the conversion succeeds. The conversion always succeeds
155 // except when the input value is special and no infinity_symbol or
156 // nan_symbol has been given to the constructor.
157 bool ToShortest(double value, StringBuilder* result_builder) const {
158 return ToShortestIeeeNumber(value, result_builder, mode: SHORTEST);
159 }
160
161 // Same as ToShortest, but for single-precision floats.
162 bool ToShortestSingle(float value, StringBuilder* result_builder) const {
163 return ToShortestIeeeNumber(value, result_builder, mode: SHORTEST_SINGLE);
164 }
165
166
167 // Computes a decimal representation with a fixed number of digits after the
168 // decimal point. The last emitted digit is rounded.
169 //
170 // Examples:
171 // ToFixed(3.12, 1) -> "3.1"
172 // ToFixed(3.1415, 3) -> "3.142"
173 // ToFixed(1234.56789, 4) -> "1234.5679"
174 // ToFixed(1.23, 5) -> "1.23000"
175 // ToFixed(0.1, 4) -> "0.1000"
176 // ToFixed(1e30, 2) -> "1000000000000000019884624838656.00"
177 // ToFixed(0.1, 30) -> "0.100000000000000005551115123126"
178 // ToFixed(0.1, 17) -> "0.10000000000000001"
179 //
180 // If requested_digits equals 0, then the tail of the result depends on
181 // the EMIT_TRAILING_DECIMAL_POINT and EMIT_TRAILING_ZERO_AFTER_POINT.
182 // Examples, for requested_digits == 0,
183 // let EMIT_TRAILING_DECIMAL_POINT and EMIT_TRAILING_ZERO_AFTER_POINT be
184 // - false and false: then 123.45 -> 123
185 // 0.678 -> 1
186 // - true and false: then 123.45 -> 123.
187 // 0.678 -> 1.
188 // - true and true: then 123.45 -> 123.0
189 // 0.678 -> 1.0
190 //
191 // Returns true if the conversion succeeds. The conversion always succeeds
192 // except for the following cases:
193 // - the input value is special and no infinity_symbol or nan_symbol has
194 // been provided to the constructor,
195 // - 'value' > 10^kMaxFixedDigitsBeforePoint, or
196 // - 'requested_digits' > kMaxFixedDigitsAfterPoint.
197 // The last two conditions imply that the result will never contain more than
198 // 1 + kMaxFixedDigitsBeforePoint + 1 + kMaxFixedDigitsAfterPoint characters
199 // (one additional character for the sign, and one for the decimal point).
200 bool ToFixed(double value,
201 int requested_digits,
202 StringBuilder* result_builder) const;
203
204 // Computes a representation in exponential format with requested_digits
205 // after the decimal point. The last emitted digit is rounded.
206 // If requested_digits equals -1, then the shortest exponential representation
207 // is computed.
208 //
209 // Examples with EMIT_POSITIVE_EXPONENT_SIGN deactivated, and
210 // exponent_character set to 'e'.
211 // ToExponential(3.12, 1) -> "3.1e0"
212 // ToExponential(5.0, 3) -> "5.000e0"
213 // ToExponential(0.001, 2) -> "1.00e-3"
214 // ToExponential(3.1415, -1) -> "3.1415e0"
215 // ToExponential(3.1415, 4) -> "3.1415e0"
216 // ToExponential(3.1415, 3) -> "3.142e0"
217 // ToExponential(123456789000000, 3) -> "1.235e14"
218 // ToExponential(1000000000000000019884624838656.0, -1) -> "1e30"
219 // ToExponential(1000000000000000019884624838656.0, 32) ->
220 // "1.00000000000000001988462483865600e30"
221 // ToExponential(1234, 0) -> "1e3"
222 //
223 // Returns true if the conversion succeeds. The conversion always succeeds
224 // except for the following cases:
225 // - the input value is special and no infinity_symbol or nan_symbol has
226 // been provided to the constructor,
227 // - 'requested_digits' > kMaxExponentialDigits.
228 // The last condition implies that the result will never contain more than
229 // kMaxExponentialDigits + 8 characters (the sign, the digit before the
230 // decimal point, the decimal point, the exponent character, the
231 // exponent's sign, and at most 3 exponent digits).
232 bool ToExponential(double value,
233 int requested_digits,
234 StringBuilder* result_builder) const;
235
236 // Computes 'precision' leading digits of the given 'value' and returns them
237 // either in exponential or decimal format, depending on
238 // max_{leading|trailing}_padding_zeroes_in_precision_mode (given to the
239 // constructor).
240 // The last computed digit is rounded.
241 //
242 // Example with max_leading_padding_zeroes_in_precision_mode = 6.
243 // ToPrecision(0.0000012345, 2) -> "0.0000012"
244 // ToPrecision(0.00000012345, 2) -> "1.2e-7"
245 // Similarily the converter may add up to
246 // max_trailing_padding_zeroes_in_precision_mode in precision mode to avoid
247 // returning an exponential representation. A zero added by the
248 // EMIT_TRAILING_ZERO_AFTER_POINT flag is counted for this limit.
249 // Examples for max_trailing_padding_zeroes_in_precision_mode = 1:
250 // ToPrecision(230.0, 2) -> "230"
251 // ToPrecision(230.0, 2) -> "230." with EMIT_TRAILING_DECIMAL_POINT.
252 // ToPrecision(230.0, 2) -> "2.3e2" with EMIT_TRAILING_ZERO_AFTER_POINT.
253 // Examples for max_trailing_padding_zeroes_in_precision_mode = 3, and no
254 // EMIT_TRAILING_ZERO_AFTER_POINT:
255 // ToPrecision(123450.0, 6) -> "123450"
256 // ToPrecision(123450.0, 5) -> "123450"
257 // ToPrecision(123450.0, 4) -> "123500"
258 // ToPrecision(123450.0, 3) -> "123000"
259 // ToPrecision(123450.0, 2) -> "1.2e5"
260 //
261 // Returns true if the conversion succeeds. The conversion always succeeds
262 // except for the following cases:
263 // - the input value is special and no infinity_symbol or nan_symbol has
264 // been provided to the constructor,
265 // - precision < kMinPericisionDigits
266 // - precision > kMaxPrecisionDigits
267 // The last condition implies that the result will never contain more than
268 // kMaxPrecisionDigits + 7 characters (the sign, the decimal point, the
269 // exponent character, the exponent's sign, and at most 3 exponent digits).
270 bool ToPrecision(double value,
271 int precision,
272 StringBuilder* result_builder) const;
273
274 enum DtoaMode {
275 // Produce the shortest correct representation.
276 // For example the output of 0.299999999999999988897 is (the less accurate
277 // but correct) 0.3.
278 SHORTEST,
279 // Same as SHORTEST, but for single-precision floats.
280 SHORTEST_SINGLE,
281 // Produce a fixed number of digits after the decimal point.
282 // For instance fixed(0.1, 4) becomes 0.1000
283 // If the input number is big, the output will be big.
284 FIXED,
285 // Fixed number of digits (independent of the decimal point).
286 PRECISION
287 };
288
289 // The maximal number of digits that are needed to emit a double in base 10.
290 // A higher precision can be achieved by using more digits, but the shortest
291 // accurate representation of any double will never use more digits than
292 // kBase10MaximalLength.
293 // Note that DoubleToAscii null-terminates its input. So the given buffer
294 // should be at least kBase10MaximalLength + 1 characters long.
295 static const int kBase10MaximalLength = 17;
296
297 // Converts the given double 'v' to digit characters. 'v' must not be NaN,
298 // +Infinity, or -Infinity. In SHORTEST_SINGLE-mode this restriction also
299 // applies to 'v' after it has been casted to a single-precision float. That
300 // is, in this mode static_cast<float>(v) must not be NaN, +Infinity or
301 // -Infinity.
302 //
303 // The result should be interpreted as buffer * 10^(point-length).
304 //
305 // The digits are written to the buffer in the platform's charset, which is
306 // often UTF-8 (with ASCII-range digits) but may be another charset, such
307 // as EBCDIC.
308 //
309 // The output depends on the given mode:
310 // - SHORTEST: produce the least amount of digits for which the internal
311 // identity requirement is still satisfied. If the digits are printed
312 // (together with the correct exponent) then reading this number will give
313 // 'v' again. The buffer will choose the representation that is closest to
314 // 'v'. If there are two at the same distance, than the one farther away
315 // from 0 is chosen (halfway cases - ending with 5 - are rounded up).
316 // In this mode the 'requested_digits' parameter is ignored.
317 // - SHORTEST_SINGLE: same as SHORTEST but with single-precision.
318 // - FIXED: produces digits necessary to print a given number with
319 // 'requested_digits' digits after the decimal point. The produced digits
320 // might be too short in which case the caller has to fill the remainder
321 // with '0's.
322 // Example: toFixed(0.001, 5) is allowed to return buffer="1", point=-2.
323 // Halfway cases are rounded towards +/-Infinity (away from 0). The call
324 // toFixed(0.15, 2) thus returns buffer="2", point=0.
325 // The returned buffer may contain digits that would be truncated from the
326 // shortest representation of the input.
327 // - PRECISION: produces 'requested_digits' where the first digit is not '0'.
328 // Even though the length of produced digits usually equals
329 // 'requested_digits', the function is allowed to return fewer digits, in
330 // which case the caller has to fill the missing digits with '0's.
331 // Halfway cases are again rounded away from 0.
332 // DoubleToAscii expects the given buffer to be big enough to hold all
333 // digits and a terminating null-character. In SHORTEST-mode it expects a
334 // buffer of at least kBase10MaximalLength + 1. In all other modes the
335 // requested_digits parameter and the padding-zeroes limit the size of the
336 // output. Don't forget the decimal point, the exponent character and the
337 // terminating null-character when computing the maximal output size.
338 // The given length is only used in debug mode to ensure the buffer is big
339 // enough.
340 static void DoubleToAscii(double v,
341 DtoaMode mode,
342 int requested_digits,
343 char* buffer,
344 int buffer_length,
345 bool* sign,
346 int* length,
347 int* point);
348
349 private:
350 // Implementation for ToShortest and ToShortestSingle.
351 bool ToShortestIeeeNumber(double value,
352 StringBuilder* result_builder,
353 DtoaMode mode) const;
354
355 // If the value is a special value (NaN or Infinity) constructs the
356 // corresponding string using the configured infinity/nan-symbol.
357 // If either of them is NULL or the value is not special then the
358 // function returns false.
359 bool HandleSpecialValues(double value, StringBuilder* result_builder) const;
360 // Constructs an exponential representation (i.e. 1.234e56).
361 // The given exponent assumes a decimal point after the first decimal digit.
362 void CreateExponentialRepresentation(const char* decimal_digits,
363 int length,
364 int exponent,
365 StringBuilder* result_builder) const;
366 // Creates a decimal representation (i.e 1234.5678).
367 void CreateDecimalRepresentation(const char* decimal_digits,
368 int length,
369 int decimal_point,
370 int digits_after_point,
371 StringBuilder* result_builder) const;
372
373 const int flags_;
374 const char* const infinity_symbol_;
375 const char* const nan_symbol_;
376 const char exponent_character_;
377 const int decimal_in_shortest_low_;
378 const int decimal_in_shortest_high_;
379 const int max_leading_padding_zeroes_in_precision_mode_;
380 const int max_trailing_padding_zeroes_in_precision_mode_;
381
382 DC_DISALLOW_IMPLICIT_CONSTRUCTORS(DoubleToStringConverter);
383};
384
385
386class StringToDoubleConverter {
387 public:
388 // Enumeration for allowing octals and ignoring junk when converting
389 // strings to numbers.
390 enum Flags {
391 NO_FLAGS = 0,
392 ALLOW_HEX = 1,
393 ALLOW_OCTALS = 2,
394 ALLOW_TRAILING_JUNK = 4,
395 ALLOW_LEADING_SPACES = 8,
396 ALLOW_TRAILING_SPACES = 16,
397 ALLOW_SPACES_AFTER_SIGN = 32,
398 ALLOW_CASE_INSENSIBILITY = 64,
399 ALLOW_HEX_FLOATS = 128,
400 };
401
402 static const uc16 kNoSeparator = '\0';
403
404 // Flags should be a bit-or combination of the possible Flags-enum.
405 // - NO_FLAGS: no special flags.
406 // - ALLOW_HEX: recognizes the prefix "0x". Hex numbers may only be integers.
407 // Ex: StringToDouble("0x1234") -> 4660.0
408 // In StringToDouble("0x1234.56") the characters ".56" are trailing
409 // junk. The result of the call is hence dependent on
410 // the ALLOW_TRAILING_JUNK flag and/or the junk value.
411 // With this flag "0x" is a junk-string. Even with ALLOW_TRAILING_JUNK,
412 // the string will not be parsed as "0" followed by junk.
413 //
414 // - ALLOW_OCTALS: recognizes the prefix "0" for octals:
415 // If a sequence of octal digits starts with '0', then the number is
416 // read as octal integer. Octal numbers may only be integers.
417 // Ex: StringToDouble("01234") -> 668.0
418 // StringToDouble("012349") -> 12349.0 // Not a sequence of octal
419 // // digits.
420 // In StringToDouble("01234.56") the characters ".56" are trailing
421 // junk. The result of the call is hence dependent on
422 // the ALLOW_TRAILING_JUNK flag and/or the junk value.
423 // In StringToDouble("01234e56") the characters "e56" are trailing
424 // junk, too.
425 // - ALLOW_TRAILING_JUNK: ignore trailing characters that are not part of
426 // a double literal.
427 // - ALLOW_LEADING_SPACES: skip over leading whitespace, including spaces,
428 // new-lines, and tabs.
429 // - ALLOW_TRAILING_SPACES: ignore trailing whitespace.
430 // - ALLOW_SPACES_AFTER_SIGN: ignore whitespace after the sign.
431 // Ex: StringToDouble("- 123.2") -> -123.2.
432 // StringToDouble("+ 123.2") -> 123.2
433 // - ALLOW_CASE_INSENSIBILITY: ignore case of characters for special values:
434 // infinity and nan.
435 // - ALLOW_HEX_FLOATS: allows hexadecimal float literals.
436 // This *must* start with "0x" and separate the exponent with "p".
437 // Examples: 0x1.2p3 == 9.0
438 // 0x10.1p0 == 16.0625
439 // ALLOW_HEX and ALLOW_HEX_FLOATS are indendent.
440 //
441 // empty_string_value is returned when an empty string is given as input.
442 // If ALLOW_LEADING_SPACES or ALLOW_TRAILING_SPACES are set, then a string
443 // containing only spaces is converted to the 'empty_string_value', too.
444 //
445 // junk_string_value is returned when
446 // a) ALLOW_TRAILING_JUNK is not set, and a junk character (a character not
447 // part of a double-literal) is found.
448 // b) ALLOW_TRAILING_JUNK is set, but the string does not start with a
449 // double literal.
450 //
451 // infinity_symbol and nan_symbol are strings that are used to detect
452 // inputs that represent infinity and NaN. They can be null, in which case
453 // they are ignored.
454 // The conversion routine first reads any possible signs. Then it compares the
455 // following character of the input-string with the first character of
456 // the infinity, and nan-symbol. If either matches, the function assumes, that
457 // a match has been found, and expects the following input characters to match
458 // the remaining characters of the special-value symbol.
459 // This means that the following restrictions apply to special-value symbols:
460 // - they must not start with signs ('+', or '-'),
461 // - they must not have the same first character.
462 // - they must not start with digits.
463 //
464 // If the separator character is not kNoSeparator, then that specific
465 // character is ignored when in between two valid digits of the significant.
466 // It is not allowed to appear in the exponent.
467 // It is not allowed to lead or trail the number.
468 // It is not allowed to appear twice next to each other.
469 //
470 // Examples:
471 // flags = ALLOW_HEX | ALLOW_TRAILING_JUNK,
472 // empty_string_value = 0.0,
473 // junk_string_value = NaN,
474 // infinity_symbol = "infinity",
475 // nan_symbol = "nan":
476 // StringToDouble("0x1234") -> 4660.0.
477 // StringToDouble("0x1234K") -> 4660.0.
478 // StringToDouble("") -> 0.0 // empty_string_value.
479 // StringToDouble(" ") -> NaN // junk_string_value.
480 // StringToDouble(" 1") -> NaN // junk_string_value.
481 // StringToDouble("0x") -> NaN // junk_string_value.
482 // StringToDouble("-123.45") -> -123.45.
483 // StringToDouble("--123.45") -> NaN // junk_string_value.
484 // StringToDouble("123e45") -> 123e45.
485 // StringToDouble("123E45") -> 123e45.
486 // StringToDouble("123e+45") -> 123e45.
487 // StringToDouble("123E-45") -> 123e-45.
488 // StringToDouble("123e") -> 123.0 // trailing junk ignored.
489 // StringToDouble("123e-") -> 123.0 // trailing junk ignored.
490 // StringToDouble("+NaN") -> NaN // NaN string literal.
491 // StringToDouble("-infinity") -> -inf. // infinity literal.
492 // StringToDouble("Infinity") -> NaN // junk_string_value.
493 //
494 // flags = ALLOW_OCTAL | ALLOW_LEADING_SPACES,
495 // empty_string_value = 0.0,
496 // junk_string_value = NaN,
497 // infinity_symbol = NULL,
498 // nan_symbol = NULL:
499 // StringToDouble("0x1234") -> NaN // junk_string_value.
500 // StringToDouble("01234") -> 668.0.
501 // StringToDouble("") -> 0.0 // empty_string_value.
502 // StringToDouble(" ") -> 0.0 // empty_string_value.
503 // StringToDouble(" 1") -> 1.0
504 // StringToDouble("0x") -> NaN // junk_string_value.
505 // StringToDouble("0123e45") -> NaN // junk_string_value.
506 // StringToDouble("01239E45") -> 1239e45.
507 // StringToDouble("-infinity") -> NaN // junk_string_value.
508 // StringToDouble("NaN") -> NaN // junk_string_value.
509 //
510 // flags = NO_FLAGS,
511 // separator = ' ':
512 // StringToDouble("1 2 3 4") -> 1234.0
513 // StringToDouble("1 2") -> NaN // junk_string_value
514 // StringToDouble("1 000 000.0") -> 1000000.0
515 // StringToDouble("1.000 000") -> 1.0
516 // StringToDouble("1.0e1 000") -> NaN // junk_string_value
517 StringToDoubleConverter(int flags,
518 double empty_string_value,
519 double junk_string_value,
520 const char* infinity_symbol,
521 const char* nan_symbol,
522 uc16 separator = kNoSeparator)
523 : flags_(flags),
524 empty_string_value_(empty_string_value),
525 junk_string_value_(junk_string_value),
526 infinity_symbol_(infinity_symbol),
527 nan_symbol_(nan_symbol),
528 separator_(separator) {
529 }
530
531 // Performs the conversion.
532 // The output parameter 'processed_characters_count' is set to the number
533 // of characters that have been processed to read the number.
534 // Spaces than are processed with ALLOW_{LEADING|TRAILING}_SPACES are included
535 // in the 'processed_characters_count'. Trailing junk is never included.
536 double StringToDouble(const char* buffer,
537 int length,
538 int* processed_characters_count) const;
539
540 // Same as StringToDouble above but for 16 bit characters.
541 double StringToDouble(const uc16* buffer,
542 int length,
543 int* processed_characters_count) const;
544
545 // Same as StringToDouble but reads a float.
546 // Note that this is not equivalent to static_cast<float>(StringToDouble(...))
547 // due to potential double-rounding.
548 float StringToFloat(const char* buffer,
549 int length,
550 int* processed_characters_count) const;
551
552 // Same as StringToFloat above but for 16 bit characters.
553 float StringToFloat(const uc16* buffer,
554 int length,
555 int* processed_characters_count) const;
556
557 private:
558 const int flags_;
559 const double empty_string_value_;
560 const double junk_string_value_;
561 const char* const infinity_symbol_;
562 const char* const nan_symbol_;
563 const uc16 separator_;
564
565 template <class Iterator>
566 double StringToIeee(Iterator start_pointer,
567 int length,
568 bool read_as_double,
569 int* processed_characters_count) const;
570
571 DC_DISALLOW_IMPLICIT_CONSTRUCTORS(StringToDoubleConverter);
572};
573
574} // namespace double_conversion
575
576#endif // DOUBLE_CONVERSION_DOUBLE_CONVERSION_H_
577

source code of qtbase/src/3rdparty/double-conversion/include/double-conversion/double-conversion.h