jsdtoa.h revision 6b15695578f07a3f72c4c9475c1a261a3021472a
/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Communicator client code, released
* March 31, 1998.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
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* either of the GNU General Public License Version 2 or later (the "GPL"),
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#ifndef jsdtoa_h___
#define jsdtoa_h___
/*
* Public interface to portable double-precision floating point to string
* and back conversion package.
*/
#include "jscompat.h"
/*
* JS_strtod() 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 the value of se is not (char **)NULL, a pointer to
* the character terminating the scan is returned in the location pointed
* to by se. If no number can be formed, se is set to s00r, and
* zero is returned.
*
* *err is set to zero on success; it's set to JS_DTOA_ERANGE on range
* errors and JS_DTOA_ENOMEM on memory failure.
*/
#define JS_DTOA_ERANGE 1
#define JS_DTOA_ENOMEM 2
JS_FRIEND_API(double)
/*
* 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)
/*
* Convert dval according to the given mode and return a pointer to the resulting ASCII string.
* 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 NULL if out of memory.
*/
JS_FRIEND_API(char *)
/*
* 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 NULL if out of memory. If the result is not NULL, it must be released via free().
*/
JS_FRIEND_API(char *)
JS_dtobasestr(int base, double d);
/*
* Clean up any persistent RAM allocated during the execution of DtoA
* routines, and remove any locks that might have been created.
*/
extern void js_FinishDtoa(void);
#endif /* jsdtoa_h___ */