From 5f8de423f190bbb79a62f804151bc24824fa32d8 Mon Sep 17 00:00:00 2001 From: "Matt A. Tobin" Date: Fri, 2 Feb 2018 04:16:08 -0500 Subject: Add m-esr52 at 52.6.0 --- js/src/jsdtoa.h | 116 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 116 insertions(+) create mode 100644 js/src/jsdtoa.h (limited to 'js/src/jsdtoa.h') diff --git a/js/src/jsdtoa.h b/js/src/jsdtoa.h new file mode 100644 index 000000000..2970ec17d --- /dev/null +++ b/js/src/jsdtoa.h @@ -0,0 +1,116 @@ +/* -*- 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 + +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 . + */ +/* 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 digits after the decimal point; exponential if number is large */ + DTOSTR_EXPONENTIAL, /* Always exponential format; significant digits */ + DTOSTR_PRECISION /* Either fixed or exponential format; 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 */ -- cgit v1.2.3