cobalt / cobalt / b15365272e6489fad522fda39eabf582f874017d / . / src / third_party / mozjs-45 / js / src / jsdtoa.h

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- | |

* vim: set ts=8 sts=4 et sw=4 tw=99: | |

* This Source Code Form is subject to the terms of the Mozilla Public | |

* License, v. 2.0. If a copy of the MPL was not distributed with this | |

* file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |

#ifndef jsdtoa_h | |

#define jsdtoa_h | |

/* | |

* Public interface to portable double-precision floating point to string | |

* and back conversion package. | |

*/ | |

#include <stddef.h> | |

struct DtoaState; | |

namespace js { | |

extern DtoaState* | |

NewDtoaState(); | |

extern void | |

DestroyDtoaState(DtoaState* state); | |

} // namespace js | |

/* | |

* js_strtod_harder() returns as a double-precision floating-point number the | |

* value represented by the character string pointed to by s00. The string is | |

* scanned up to the first unrecognized character. | |

* | |

* If se is not nullptr, *se receives a pointer to the character terminating | |

* the scan. If no number can be formed, *se receives a pointer to the first | |

* unparseable character in s00, and zero is returned. | |

* | |

* On overflow, this function returns infinity and does not indicate an error. | |

* | |

* *err is set to zero on success; it's set to JS_DTOA_ENOMEM on memory failure. | |

*/ | |

#define JS_DTOA_ENOMEM 2 | |

double | |

js_strtod_harder(DtoaState* state, const char* s00, char** se, int* err); | |

/* | |

* Modes for converting floating-point numbers to strings. | |

* | |

* Some of the modes can round-trip; this means that if the number is converted to | |

* a string using one of these mode and then converted back to a number, the result | |

* will be identical to the original number (except that, due to ECMA, -0 will get converted | |

* to +0). These round-trip modes return the minimum number of significand digits that | |

* permit the round trip. | |

* | |

* Some of the modes take an integer parameter <precision>. | |

*/ | |

/* NB: Keep this in sync with number_constants[]. */ | |

typedef enum JSDToStrMode { | |

DTOSTR_STANDARD, /* Either fixed or exponential format; round-trip */ | |

DTOSTR_STANDARD_EXPONENTIAL, /* Always exponential format; round-trip */ | |

DTOSTR_FIXED, /* Round to <precision> digits after the decimal point; exponential if number is large */ | |

DTOSTR_EXPONENTIAL, /* Always exponential format; <precision> significant digits */ | |

DTOSTR_PRECISION /* Either fixed or exponential format; <precision> significant digits */ | |

} JSDToStrMode; | |

/* Maximum number of characters (including trailing null) that a DTOSTR_STANDARD or DTOSTR_STANDARD_EXPONENTIAL | |

* conversion can produce. This maximum is reached for a number like -0.0000012345678901234567. */ | |

#define DTOSTR_STANDARD_BUFFER_SIZE 26 | |

/* Maximum number of characters (including trailing null) that one of the other conversions | |

* can produce. This maximum is reached for TO_FIXED, which can generate up to 21 digits before the decimal point. */ | |

#define DTOSTR_VARIABLE_BUFFER_SIZE(precision) ((precision)+24 > DTOSTR_STANDARD_BUFFER_SIZE ? (precision)+24 : DTOSTR_STANDARD_BUFFER_SIZE) | |

/* | |

* DO NOT USE THIS FUNCTION IF YOU CAN AVOID IT. js::NumberToCString() is a | |

* better function to use. | |

* | |

* Convert dval according to the given mode and return a pointer to the | |

* resulting ASCII string. If mode == DTOSTR_STANDARD and precision == 0 it's | |

* equivalent to ToString() as specified by ECMA-262-5 section 9.8.1, but it | |

* doesn't handle integers specially so should be avoided in that case (that's | |

* why js::NumberToCString() is better). | |

* | |

* The result is held somewhere in buffer, but not necessarily at the | |

* beginning. The size of buffer is given in bufferSize, and must be at least | |

* as large as given by the above macros. | |

* | |

* Return nullptr if out of memory. | |

*/ | |

char* | |

js_dtostr(DtoaState* state, char* buffer, size_t bufferSize, JSDToStrMode mode, int precision, | |

double dval); | |

/* | |

* DO NOT USE THIS FUNCTION IF YOU CAN AVOID IT. js::NumberToCString() is a | |

* better function to use. | |

* | |

* Convert d to a string in the given base. The integral part of d will be | |

* printed exactly in that base, regardless of how large it is, because there | |

* is no exponential notation for non-base-ten numbers. The fractional part | |

* will be rounded to as few digits as possible while still preserving the | |

* round-trip property (analogous to that of printing decimal numbers). In | |

* other words, if one were to read the resulting string in via a hypothetical | |

* base-number-reading routine that rounds to the nearest IEEE double (and to | |

* an even significand if there are two equally near doubles), then the result | |

* would equal d (except for -0.0, which converts to "0", and NaN, which is | |

* not equal to itself). | |

* | |

* Return nullptr if out of memory. If the result is not nullptr, it must be | |

* released via js_free(). | |

*/ | |

char* | |

js_dtobasestr(DtoaState* state, int base, double d); | |

#endif /* jsdtoa_h */ |