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comparison: js/src/jsdtoa.h
js/src/jsdtoa.h
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- TOR_BUG_3246
- changeset 7
- 129ffea94266
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| -1:000000000000 | 0:c36d1925c94a |
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| 1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- | |
| 2 * vim: set ts=8 sts=4 et sw=4 tw=99: | |
| 3 * This Source Code Form is subject to the terms of the Mozilla Public | |
| 4 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 6 | |
| 7 #ifndef jsdtoa_h | |
| 8 #define jsdtoa_h | |
| 9 | |
| 10 /* | |
| 11 * Public interface to portable double-precision floating point to string | |
| 12 * and back conversion package. | |
| 13 */ | |
| 14 | |
| 15 #include <stddef.h> | |
| 16 | |
| 17 struct DtoaState; | |
| 18 | |
| 19 DtoaState * | |
| 20 js_NewDtoaState(); | |
| 21 | |
| 22 void | |
| 23 js_DestroyDtoaState(DtoaState *state); | |
| 24 | |
| 25 /* | |
| 26 * js_strtod_harder() returns as a double-precision floating-point number the | |
| 27 * value represented by the character string pointed to by s00. The string is | |
| 28 * scanned up to the first unrecognized character. | |
| 29 * | |
| 30 * If se is not nullptr, *se receives a pointer to the character terminating | |
| 31 * the scan. If no number can be formed, *se receives a pointer to the first | |
| 32 * unparseable character in s00, and zero is returned. | |
| 33 * | |
| 34 * On overflow, this function returns infinity and does not indicate an error. | |
| 35 * | |
| 36 * *err is set to zero on success; it's set to JS_DTOA_ENOMEM on memory failure. | |
| 37 */ | |
| 38 #define JS_DTOA_ENOMEM 2 | |
| 39 double | |
| 40 js_strtod_harder(DtoaState *state, const char *s00, char **se, int *err); | |
| 41 | |
| 42 /* | |
| 43 * Modes for converting floating-point numbers to strings. | |
| 44 * | |
| 45 * Some of the modes can round-trip; this means that if the number is converted to | |
| 46 * a string using one of these mode and then converted back to a number, the result | |
| 47 * will be identical to the original number (except that, due to ECMA, -0 will get converted | |
| 48 * to +0). These round-trip modes return the minimum number of significand digits that | |
| 49 * permit the round trip. | |
| 50 * | |
| 51 * Some of the modes take an integer parameter <precision>. | |
| 52 */ | |
| 53 /* NB: Keep this in sync with number_constants[]. */ | |
| 54 typedef enum JSDToStrMode { | |
| 55 DTOSTR_STANDARD, /* Either fixed or exponential format; round-trip */ | |
| 56 DTOSTR_STANDARD_EXPONENTIAL, /* Always exponential format; round-trip */ | |
| 57 DTOSTR_FIXED, /* Round to <precision> digits after the decimal point; exponential if number is large */ | |
| 58 DTOSTR_EXPONENTIAL, /* Always exponential format; <precision> significant digits */ | |
| 59 DTOSTR_PRECISION /* Either fixed or exponential format; <precision> significant digits */ | |
| 60 } JSDToStrMode; | |
| 61 | |
| 62 | |
| 63 /* Maximum number of characters (including trailing null) that a DTOSTR_STANDARD or DTOSTR_STANDARD_EXPONENTIAL | |
| 64 * conversion can produce. This maximum is reached for a number like -0.0000012345678901234567. */ | |
| 65 #define DTOSTR_STANDARD_BUFFER_SIZE 26 | |
| 66 | |
| 67 /* Maximum number of characters (including trailing null) that one of the other conversions | |
| 68 * can produce. This maximum is reached for TO_FIXED, which can generate up to 21 digits before the decimal point. */ | |
| 69 #define DTOSTR_VARIABLE_BUFFER_SIZE(precision) ((precision)+24 > DTOSTR_STANDARD_BUFFER_SIZE ? (precision)+24 : DTOSTR_STANDARD_BUFFER_SIZE) | |
| 70 | |
| 71 /* | |
| 72 * DO NOT USE THIS FUNCTION IF YOU CAN AVOID IT. js::NumberToCString() is a | |
| 73 * better function to use. | |
| 74 * | |
| 75 * Convert dval according to the given mode and return a pointer to the | |
| 76 * resulting ASCII string. If mode == DTOSTR_STANDARD and precision == 0 it's | |
| 77 * equivalent to ToString() as specified by ECMA-262-5 section 9.8.1, but it | |
| 78 * doesn't handle integers specially so should be avoided in that case (that's | |
| 79 * why js::NumberToCString() is better). | |
| 80 * | |
| 81 * The result is held somewhere in buffer, but not necessarily at the | |
| 82 * beginning. The size of buffer is given in bufferSize, and must be at least | |
| 83 * as large as given by the above macros. | |
| 84 * | |
| 85 * Return nullptr if out of memory. | |
| 86 */ | |
| 87 char * | |
| 88 js_dtostr(DtoaState *state, char *buffer, size_t bufferSize, JSDToStrMode mode, int precision, | |
| 89 double dval); | |
| 90 | |
| 91 /* | |
| 92 * DO NOT USE THIS FUNCTION IF YOU CAN AVOID IT. js::NumberToCString() is a | |
| 93 * better function to use. | |
| 94 * | |
| 95 * Convert d to a string in the given base. The integral part of d will be | |
| 96 * printed exactly in that base, regardless of how large it is, because there | |
| 97 * is no exponential notation for non-base-ten numbers. The fractional part | |
| 98 * will be rounded to as few digits as possible while still preserving the | |
| 99 * round-trip property (analogous to that of printing decimal numbers). In | |
| 100 * other words, if one were to read the resulting string in via a hypothetical | |
| 101 * base-number-reading routine that rounds to the nearest IEEE double (and to | |
| 102 * an even significand if there are two equally near doubles), then the result | |
| 103 * would equal d (except for -0.0, which converts to "0", and NaN, which is | |
| 104 * not equal to itself). | |
| 105 * | |
| 106 * Return nullptr if out of memory. If the result is not nullptr, it must be | |
| 107 * released via js_free(). | |
| 108 */ | |
| 109 char * | |
| 110 js_dtobasestr(DtoaState *state, int base, double d); | |
| 111 | |
| 112 #endif /* jsdtoa_h */ |
