| // Copyright 2010 the V8 project authors. All rights reserved. | |
| // Redistribution and use in source and binary forms, with or without | |
| // modification, are permitted provided that the following conditions are | |
| // met: | |
| // | |
| // * Redistributions of source code must retain the above copyright | |
| // notice, this list of conditions and the following disclaimer. | |
| // * Redistributions in binary form must reproduce the above | |
| // copyright notice, this list of conditions and the following | |
| // disclaimer in the documentation and/or other materials provided | |
| // with the distribution. | |
| // * Neither the name of Google Inc. nor the names of its | |
| // contributors may be used to endorse or promote products derived | |
| // from this software without specific prior written permission. | |
| // | |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
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| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
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| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| namespace double_conversion { | |
| enum FastDtoaMode { | |
| // Computes the shortest representation of the given input. The returned | |
| // result will be the most accurate number of this length. Longer | |
| // representations might be more accurate. | |
| FAST_DTOA_SHORTEST, | |
| // Same as FAST_DTOA_SHORTEST but for single-precision floats. | |
| FAST_DTOA_SHORTEST_SINGLE, | |
| // Computes a representation where the precision (number of digits) is | |
| // given as input. The precision is independent of the decimal point. | |
| FAST_DTOA_PRECISION | |
| }; | |
| // FastDtoa will produce at most kFastDtoaMaximalLength digits. This does not | |
| // include the terminating '\0' character. | |
| static const int kFastDtoaMaximalLength = 17; | |
| // Same for single-precision numbers. | |
| static const int kFastDtoaMaximalSingleLength = 9; | |
| // Provides a decimal representation of v. | |
| // The result should be interpreted as buffer * 10^(point - length). | |
| // | |
| // Precondition: | |
| // * v must be a strictly positive finite double. | |
| // | |
| // Returns true if it succeeds, otherwise the result can not be trusted. | |
| // There will be *length digits inside the buffer followed by a null terminator. | |
| // If the function returns true and mode equals | |
| // - FAST_DTOA_SHORTEST, then | |
| // the parameter requested_digits is ignored. | |
| // The result satisfies | |
| // v == (double) (buffer * 10^(point - length)). | |
| // The digits in the buffer are the shortest representation possible. E.g. | |
| // if 0.099999999999 and 0.1 represent the same double then "1" is returned | |
| // with point = 0. | |
| // The last digit will be closest to the actual v. That is, even if several | |
| // digits might correctly yield 'v' when read again, the buffer will contain | |
| // the one closest to v. | |
| // - FAST_DTOA_PRECISION, then | |
| // the buffer contains requested_digits digits. | |
| // the difference v - (buffer * 10^(point-length)) is closest to zero for | |
| // all possible representations of requested_digits digits. | |
| // If there are two values that are equally close, then FastDtoa returns | |
| // false. | |
| // For both modes the buffer must be large enough to hold the result. | |
| bool FastDtoa(double d, | |
| FastDtoaMode mode, | |
| int requested_digits, | |
| Vector<char> buffer, | |
| int* length, | |
| int* decimal_point); | |
| } // namespace double_conversion | |