Skip to content

M
mruby
Unverified Commit bf523b71 authored by Yukihiro "Matz" Matsumoto's avatar Yukihiro "Matz" Matsumoto
Browse files
Options

strtod.c: new public domain implementation of `strtod`; ref #5448 

Instead of using copyrighted `strtod`, now use the public domain
implementation of `strtod` by Yasuhiro Matsumoto (@mattn). The function
has been renamed to `mrb_float_read()`; ref #5460 as well.
parent a44ca2e9
Hide whitespace changes
Inline Side-by-side
Showing with 120 additions and 247 deletions
src/string.c
View file @ bf523b71
......@@ -2922,250 +2922,3 @@ mrb_init_string(mrb_state *mrb)
mrb_define_method(mrb, s, "setbyte", mrb_str_setbyte, MRB_ARGS_REQ(2));
mrb_define_method(mrb, s, "byteslice", mrb_str_byteslice, MRB_ARGS_ARG(1,1));
}
#ifndef MRB_NO_FLOAT
/*
* Source code for the "strtod" library procedure.
*
* Copyright (c) 1988-1993 The Regents of the University of California.
* Copyright (c) 1994 Sun Microsystems, Inc.
*
* Permission to use, copy, modify, and distribute this
* software and its documentation for any purpose and without
* fee is hereby granted, provided that the above copyright
* notice appear in all copies. The University of California
* makes no representations about the suitability of this
* software for any purpose. It is provided "as is" without
* express or implied warranty.
*
* RCS: @(#) $Id: strtod.c 11708 2007-02-12 23:01:19Z shyouhei $
*/
#include <ctype.h>
#include <errno.h>
static const int maxExponent = 511; /* Largest possible base 10 exponent. Any
* exponent larger than this will already
* produce underflow or overflow, so there's
* no need to worry about additional digits.
*/
static const double powersOf10[] = {/* Table giving binary powers of 10. Entry */
10., /* is 10^2^i. Used to convert decimal */
100., /* exponents into floating-point numbers. */
1.0e4,
1.0e8,
1.0e16,
1.0e32,
1.0e64,
1.0e128,
1.0e256
};
MRB_API double
mrb_float_read(const char *string, char **endPtr)
/* const char *string; A decimal ASCII floating-point number,
* optionally preceded by white space.
* Must have form "-I.FE-X", where I is the
* integer part of the mantissa, F is the
* fractional part of the mantissa, and X
* is the exponent. Either of the signs
* may be "+", "-", or omitted. Either I
* or F may be omitted, or both. The decimal
* point isn't necessary unless F is present.
* The "E" may actually be an "e". E and X
* may both be omitted (but not just one).
*/
/* char **endPtr; If non-NULL, store terminating character's
* address here. */
{
int sign, expSign = FALSE;
double fraction, dblExp;
const double *d;
const char *p;
int c;
int exp = 0; /* Exponent read from "EX" field. */
int fracExp = 0; /* Exponent that derives from the fractional
* part. Under normal circumstances, it is
* the negative of the number of digits in F.
* However, if I is very long, the last digits
* of I get dropped (otherwise a long I with a
* large negative exponent could cause an
* unnecessary overflow on I alone). In this
* case, fracExp is incremented one for each
* dropped digit. */
int mantSize; /* Number of digits in mantissa. */
int decPt; /* Number of mantissa digits BEFORE decimal
* point. */
const char *pExp; /* Temporarily holds location of exponent
* in string. */
/*
* Strip off leading blanks and check for a sign.
*/
p = string;
while (ISSPACE(*p)) {
p += 1;
}
if (*p == '-') {
sign = TRUE;
p += 1;
}
else {
if (*p == '+') {
p += 1;
}
sign = FALSE;
}
/*
* Count the number of digits in the mantissa (including the decimal
* point), and also locate the decimal point.
*/
decPt = -1;
for (mantSize = 0; ; mantSize += 1)
{
c = *p;
if (!ISDIGIT(c)) {
if ((c != '.') || (decPt >= 0)) {
break;
}
decPt = mantSize;
}
p += 1;
}
/*
* Now suck up the digits in the mantissa. Use two integers to
* collect 9 digits each (this is faster than using floating-point).
* If the mantissa has more than 18 digits, ignore the extras, since
* they can't affect the value anyway.
*/
pExp = p;
p -= mantSize;
if (decPt < 0) {
decPt = mantSize;
}
else {
mantSize -= 1; /* One of the digits was the point. */
}
if (mantSize > 18) {
if (decPt - 18 > 29999) {
fracExp = 29999;
}
else {
fracExp = decPt - 18;
}
mantSize = 18;
}
else {
fracExp = decPt - mantSize;
}
if (mantSize == 0) {
fraction = 0.0;
p = string;
goto done;
}
else {
int frac1, frac2;
frac1 = 0;
for ( ; mantSize > 9; mantSize -= 1)
{
c = *p;
p += 1;
if (c == '.') {
c = *p;
p += 1;
}
frac1 = 10*frac1 + (c - '0');
}
frac2 = 0;
for (; mantSize > 0; mantSize -= 1)
{
c = *p;
p += 1;
if (c == '.') {
c = *p;
p += 1;
}
frac2 = 10*frac2 + (c - '0');
}
fraction = (1.0e9 * frac1) + frac2;
}
/*
* Skim off the exponent.
*/
p = pExp;
if ((*p == 'E') || (*p == 'e')) {
p += 1;
if (*p == '-') {
expSign = TRUE;
p += 1;
}
else {
if (*p == '+') {
p += 1;
}
expSign = FALSE;
}
while (ISDIGIT(*p)) {
exp = exp * 10 + (*p - '0');
if (exp > 19999) {
exp = 19999;
}
p += 1;
}
}
if (expSign) {
exp = fracExp - exp;
}
else {
exp = fracExp + exp;
}
/*
* Generate a floating-point number that represents the exponent.
* Do this by processing the exponent one bit at a time to combine
* many powers of 2 of 10. Then combine the exponent with the
* fraction.
*/
if (exp < 0) {
expSign = TRUE;
exp = -exp;
}
else {
expSign = FALSE;
}
if (exp > maxExponent) {
exp = maxExponent;
errno = ERANGE;
}
dblExp = 1.0;
for (d = powersOf10; exp != 0; exp >>= 1, d += 1) {
if (exp & 01) {
dblExp *= *d;
}
}
if (expSign) {
fraction /= dblExp;
}
else {
fraction *= dblExp;
}
done:
if (endPtr != NULL) {
*endPtr = (char *) p;
}
if (sign) {
return -fraction;
}
return fraction;
}
#endif
src/strtod.c 0 → 100644
View file @ bf523b71
#include <mruby.h>
#ifndef MRB_NO_FLOAT
/*
* strtod implementation.
* author: Yasuhiro Matsumoto (@mattn)
* license: public domain
*/
/*
The original code can be found in https://github.com/mattn/strtod
I modified the routine for mruby:
* renamed the function `vim_strtod` -> `mrb_float_read`
* simplified the code
My modifications in this file are also placed in the public domain.
Matz (Yukihiro Matsumoto)
*/
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <errno.h>
MRB_API double
mrb_float_read(const char *str, char **end)
{
double d = 0.0;
int sign;
int n = 0;
const char *p, *a;
a = p = str;
while (ISSPACE(*p))
++p;
/* decimal part */
sign = 1;
if (*p == '-') {
sign = -1;
++p;
} else if (*p == '+')
++p;
if (ISDIGIT(*p)) {
d = (double)(*p++ - '0');
while (*p && ISDIGIT(*p)) {
d = d * 10.0 + (double)(*p - '0');
++p;
++n;
}
a = p;
} else if (*p != '.')
goto done;
d *= sign;
/* fraction part */
if (*p == '.') {
double f = 0.0;
double base = 0.1;
++p;
if (ISDIGIT(*p))
{
while (*p && ISDIGIT(*p)) {
f += base * (*p - '0') ;
base /= 10.0;
++p;
++n;
}
}
d += f * sign;
a = p;
}
/* exponential part */
if ((*p == 'E') || (*p == 'e')) {
int e = 0;
++p;
sign = 1;
if (*p == '-') {
sign = -1;
++p;
} else if (*p == '+')
++p;
if (ISDIGIT(*p)) {
while (*p == '0')
++p;
if (*p == '\0') --p;
e = (int)(*p++ - '0');
for (; *p && ISDIGIT(*p); p++) {
if (e < 10000)
e = e * 10 + (*p - '0');
}
e *= sign;
}
else if (!ISDIGIT(*(a-1))) {
a = str;
goto done;
}
else if (*p == 0)
goto done;
d *= pow(10.0, (double) e);
a = p;
}
else if (p > str && !ISDIGIT(*(p-1))) {
a = str;
goto done;
}
done:
if (end)
*end = (char*)a;
return d;
}
#endif
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment