| 1 | // Copyright 2010 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_BIGNUM_DTOA_H_ |
|---|
| 29 | #define DOUBLE_CONVERSION_BIGNUM_DTOA_H_ |
|---|
| 30 | |
|---|
| 31 | #include <double-conversion/utils.h> |
|---|
| 32 | |
|---|
| 33 | namespace double_conversion { |
|---|
| 34 | |
|---|
| 35 | enum BignumDtoaMode { |
|---|
| 36 | // Return the shortest correct representation. |
|---|
| 37 | // For example the output of 0.299999999999999988897 is (the less accurate but |
|---|
| 38 | // correct) 0.3. |
|---|
| 39 | BIGNUM_DTOA_SHORTEST, |
|---|
| 40 | // Same as BIGNUM_DTOA_SHORTEST but for single-precision floats. |
|---|
| 41 | BIGNUM_DTOA_SHORTEST_SINGLE, |
|---|
| 42 | // Return a fixed number of digits after the decimal point. |
|---|
| 43 | // For instance fixed(0.1, 4) becomes 0.1000 |
|---|
| 44 | // If the input number is big, the output will be big. |
|---|
| 45 | BIGNUM_DTOA_FIXED, |
|---|
| 46 | // Return a fixed number of digits, no matter what the exponent is. |
|---|
| 47 | BIGNUM_DTOA_PRECISION |
|---|
| 48 | }; |
|---|
| 49 | |
|---|
| 50 | // Converts the given double 'v' to ascii. |
|---|
| 51 | // The result should be interpreted as buffer * 10^(point-length). |
|---|
| 52 | // The buffer will be null-terminated. |
|---|
| 53 | // |
|---|
| 54 | // The input v must be > 0 and different from NaN, and Infinity. |
|---|
| 55 | // |
|---|
| 56 | // The output depends on the given mode: |
|---|
| 57 | // - SHORTEST: produce the least amount of digits for which the internal |
|---|
| 58 | // identity requirement is still satisfied. If the digits are printed |
|---|
| 59 | // (together with the correct exponent) then reading this number will give |
|---|
| 60 | // 'v' again. The buffer will choose the representation that is closest to |
|---|
| 61 | // 'v'. If there are two at the same distance, than the number is round up. |
|---|
| 62 | // In this mode the 'requested_digits' parameter is ignored. |
|---|
| 63 | // - FIXED: produces digits necessary to print a given number with |
|---|
| 64 | // 'requested_digits' digits after the decimal point. The produced digits |
|---|
| 65 | // might be too short in which case the caller has to fill the gaps with '0's. |
|---|
| 66 | // Example: toFixed(0.001, 5) is allowed to return buffer="1", point=-2. |
|---|
| 67 | // Halfway cases are rounded up. The call toFixed(0.15, 2) thus returns |
|---|
| 68 | // buffer="2", point=0. |
|---|
| 69 | // Note: the length of the returned buffer has no meaning wrt the significance |
|---|
| 70 | // of its digits. That is, just because it contains '0's does not mean that |
|---|
| 71 | // any other digit would not satisfy the internal identity requirement. |
|---|
| 72 | // - PRECISION: produces 'requested_digits' where the first digit is not '0'. |
|---|
| 73 | // Even though the length of produced digits usually equals |
|---|
| 74 | // 'requested_digits', the function is allowed to return fewer digits, in |
|---|
| 75 | // which case the caller has to fill the missing digits with '0's. |
|---|
| 76 | // Halfway cases are again rounded up. |
|---|
| 77 | // 'BignumDtoa' expects the given buffer to be big enough to hold all digits |
|---|
| 78 | // and a terminating null-character. |
|---|
| 79 | void BignumDtoa(double v, BignumDtoaMode mode, int requested_digits, |
|---|
| 80 | Vector<char> buffer, int* length, int* point); |
|---|
| 81 | |
|---|
| 82 | } // namespace double_conversion |
|---|
| 83 | |
|---|
| 84 | #endif // DOUBLE_CONVERSION_BIGNUM_DTOA_H_ |
|---|
| 85 | |
|---|
