1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
2 *
3 * ***** BEGIN LICENSE BLOCK *****
4 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
5 *
6 * The contents of this file are subject to the Mozilla Public License Version
7 * 1.1 (the "License"); you may not use this file except in compliance with
8 * the License. You may obtain a copy of the License at
9 * http://www.mozilla.org/MPL/
10 *
11 * Software distributed under the License is distributed on an "AS IS" basis,
12 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
13 * for the specific language governing rights and limitations under the
14 * License.
15 *
16 * The Original Code is Mozilla Communicator client code, released
17 * March 31, 1998.
18 *
19 * The Initial Developer of the Original Code is
20 * Netscape Communications Corporation.
21 * Portions created by the Initial Developer are Copyright (C) 1998
22 * the Initial Developer. All Rights Reserved.
23 *
24 * Contributor(s):
25 *
26 * Alternatively, the contents of this file may be used under the terms of
27 * either of the GNU General Public License Version 2 or later (the "GPL"),
28 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
29 * in which case the provisions of the GPL or the LGPL are applicable instead
30 * of those above. If you wish to allow use of your version of this file only
31 * under the terms of either the GPL or the LGPL, and not to allow others to
32 * use your version of this file under the terms of the MPL, indicate your
33 * decision by deleting the provisions above and replace them with the notice
34 * and other provisions required by the GPL or the LGPL. If you do not delete
35 * the provisions above, a recipient may use your version of this file under
36 * the terms of any one of the MPL, the GPL or the LGPL.
37 *
38 * ***** END LICENSE BLOCK ***** */
40 #ifndef jsdtoa_h___
41 #define jsdtoa_h___
42 /*
43 * Public interface to portable double-precision floating point to string
44 * and back conversion package.
45 */
47 #include "jscompat.h"
49 JS_BEGIN_EXTERN_C
51 /*
52 * JS_strtod() returns as a double-precision floating-point number
53 * the value represented by the character string pointed to by
54 * s00. The string is scanned up to the first unrecognized
55 * character.
56 * If the value of se is not (char **)NULL, a pointer to
57 * the character terminating the scan is returned in the location pointed
58 * to by se. If no number can be formed, se is set to s00r, and
59 * zero is returned.
60 *
61 * *err is set to zero on success; it's set to JS_DTOA_ERANGE on range
62 * errors and JS_DTOA_ENOMEM on memory failure.
63 */
64 #define JS_DTOA_ERANGE 1
65 #define JS_DTOA_ENOMEM 2
66 JS_FRIEND_API(double)
67 JS_strtod(const char *s00, char **se, int *err);
69 /*
70 * Modes for converting floating-point numbers to strings.
71 *
72 * Some of the modes can round-trip; this means that if the number is converted to
73 * a string using one of these mode and then converted back to a number, the result
74 * will be identical to the original number (except that, due to ECMA, -0 will get converted
75 * to +0). These round-trip modes return the minimum number of significand digits that
76 * permit the round trip.
77 *
78 * Some of the modes take an integer parameter <precision>.
79 */
80 /* NB: Keep this in sync with number_constants[]. */
81 typedef enum JSDToStrMode {
82 DTOSTR_STANDARD, /* Either fixed or exponential format; round-trip */
83 DTOSTR_STANDARD_EXPONENTIAL, /* Always exponential format; round-trip */
84 DTOSTR_FIXED, /* Round to <precision> digits after the decimal point; exponential if number is large */
85 DTOSTR_EXPONENTIAL, /* Always exponential format; <precision> significant digits */
86 DTOSTR_PRECISION /* Either fixed or exponential format; <precision> significant digits */
87 } JSDToStrMode;
90 /* Maximum number of characters (including trailing null) that a DTOSTR_STANDARD or DTOSTR_STANDARD_EXPONENTIAL
91 * conversion can produce. This maximum is reached for a number like -0.0000012345678901234567. */
92 #define DTOSTR_STANDARD_BUFFER_SIZE 26
94 /* Maximum number of characters (including trailing null) that one of the other conversions
95 * can produce. This maximum is reached for TO_FIXED, which can generate up to 21 digits before the decimal point. */
96 #define DTOSTR_VARIABLE_BUFFER_SIZE(precision) ((precision)+24 > DTOSTR_STANDARD_BUFFER_SIZE ? (precision)+24 : DTOSTR_STANDARD_BUFFER_SIZE)
98 /*
99 * Convert dval according to the given mode and return a pointer to the resulting ASCII string.
100 * The result is held somewhere in buffer, but not necessarily at the beginning. The size of
101 * buffer is given in bufferSize, and must be at least as large as given by the above macros.
102 *
103 * Return NULL if out of memory.
104 */
105 JS_FRIEND_API(char *)
106 JS_dtostr(char *buffer, size_t bufferSize, JSDToStrMode mode, int precision, double dval);
108 /*
109 * Convert d to a string in the given base. The integral part of d will be printed exactly
110 * in that base, regardless of how large it is, because there is no exponential notation for non-base-ten
111 * numbers. The fractional part will be rounded to as few digits as possible while still preserving
112 * the round-trip property (analogous to that of printing decimal numbers). In other words, if one were
113 * to read the resulting string in via a hypothetical base-number-reading routine that rounds to the nearest
114 * IEEE double (and to an even significand if there are two equally near doubles), then the result would
115 * equal d (except for -0.0, which converts to "0", and NaN, which is not equal to itself).
116 *
117 * Return NULL if out of memory. If the result is not NULL, it must be released via free().
118 */
119 JS_FRIEND_API(char *)
120 JS_dtobasestr(int base, double d);
122 /*
123 * Clean up any persistent RAM allocated during the execution of DtoA
124 * routines, and remove any locks that might have been created.
125 */
126 extern void js_FinishDtoa(void);
128 JS_END_EXTERN_C
130 #endif /* jsdtoa_h___ */