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 2010 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_BIGNUM_DTOA_H_ |
| 38 | #define DOUBLE_CONVERSION_BIGNUM_DTOA_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 | enum BignumDtoaMode { |
| 50 | // Return the shortest correct representation. |
| 51 | // For example the output of 0.299999999999999988897 is (the less accurate but |
| 52 | // correct) 0.3. |
| 53 | BIGNUM_DTOA_SHORTEST, |
| 54 | // Same as BIGNUM_DTOA_SHORTEST but for single-precision floats. |
| 55 | BIGNUM_DTOA_SHORTEST_SINGLE, |
| 56 | // Return a fixed number of digits after the decimal point. |
| 57 | // For instance fixed(0.1, 4) becomes 0.1000 |
| 58 | // If the input number is big, the output will be big. |
| 59 | BIGNUM_DTOA_FIXED, |
| 60 | // Return a fixed number of digits, no matter what the exponent is. |
| 61 | BIGNUM_DTOA_PRECISION |
| 62 | }; |
| 63 | |
| 64 | // Converts the given double 'v' to ascii. |
| 65 | // The result should be interpreted as buffer * 10^(point-length). |
| 66 | // The buffer will be null-terminated. |
| 67 | // |
| 68 | // The input v must be > 0 and different from NaN, and Infinity. |
| 69 | // |
| 70 | // The output depends on the given mode: |
| 71 | // - SHORTEST: produce the least amount of digits for which the internal |
| 72 | // identity requirement is still satisfied. If the digits are printed |
| 73 | // (together with the correct exponent) then reading this number will give |
| 74 | // 'v' again. The buffer will choose the representation that is closest to |
| 75 | // 'v'. If there are two at the same distance, than the number is round up. |
| 76 | // In this mode the 'requested_digits' parameter is ignored. |
| 77 | // - FIXED: produces digits necessary to print a given number with |
| 78 | // 'requested_digits' digits after the decimal point. The produced digits |
| 79 | // might be too short in which case the caller has to fill the gaps with '0's. |
| 80 | // Example: toFixed(0.001, 5) is allowed to return buffer="1", point=-2. |
| 81 | // Halfway cases are rounded up. The call toFixed(0.15, 2) thus returns |
| 82 | // buffer="2", point=0. |
| 83 | // Note: the length of the returned buffer has no meaning wrt the significance |
| 84 | // of its digits. That is, just because it contains '0's does not mean that |
| 85 | // any other digit would not satisfy the internal identity requirement. |
| 86 | // - PRECISION: produces 'requested_digits' where the first digit is not '0'. |
| 87 | // Even though the length of produced digits usually equals |
| 88 | // 'requested_digits', the function is allowed to return fewer digits, in |
| 89 | // which case the caller has to fill the missing digits with '0's. |
| 90 | // Halfway cases are again rounded up. |
| 91 | // 'BignumDtoa' expects the given buffer to be big enough to hold all digits |
| 92 | // and a terminating null-character. |
| 93 | void BignumDtoa(double v, BignumDtoaMode mode, int requested_digits, |
| 94 | Vector<char> buffer, int* length, int* point); |
| 95 | |
| 96 | } // namespace double_conversion |
| 97 | |
| 98 | // ICU PATCH: Close ICU namespace |
| 99 | U_NAMESPACE_END |
| 100 | |
| 101 | #endif // DOUBLE_CONVERSION_BIGNUM_DTOA_H_ |
| 102 | #endif // ICU PATCH: close #if !UCONFIG_NO_FORMATTING |