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-rw-r--r--Python/strtod.c212
1 files changed, 106 insertions, 106 deletions
diff --git a/Python/strtod.c b/Python/strtod.c
index 5c084a4de0..6798efa927 100644
--- a/Python/strtod.c
+++ b/Python/strtod.c
@@ -14,7 +14,7 @@
Defines: double strtod (char *str, char**ptr)
*/
-/* This is an implementation of the strtod() function described in the
+/* This is an implementation of the strtod() function described in the
System V manuals, with a different name to avoid linker problems.
All that str2dbl() does itself is check that the argument is well-formed
and is in range. It leaves the work of conversion to atof(), which is
@@ -22,18 +22,18 @@
There are two reasons why this should be provided to the net:
(a) some UNIX systems do not yet have strtod(), or do not have it
- available in the BSD "universe" (but they do have atof()).
+ available in the BSD "universe" (but they do have atof()).
(b) some of the UNIX systems that *do* have it get it wrong.
- (some crash with large arguments, some assign the wrong *ptr value).
+ (some crash with large arguments, some assign the wrong *ptr value).
There is a reason why *we* are providing it: we need a correct version
of strtod(), and if we give this one away maybe someone will look for
mistakes in it and fix them for us (:-).
*/
-
+
/* The following constants are machine-specific. MD{MIN,MAX}EXPT are
integers and MD{MIN,MAX}FRAC are strings such that
- 0.${MDMAXFRAC}e${MDMAXEXPT} is the largest representable double,
- 0.${MDMINFRAC}e${MDMINEXPT} is the smallest representable +ve double
+ 0.${MDMAXFRAC}e${MDMAXEXPT} is the largest representable double,
+ 0.${MDMINFRAC}e${MDMINEXPT} is the smallest representable +ve double
MD{MIN,MAX}FRAC must not have any trailing zeros.
The values here are for IEEE-754 64-bit floats.
It is not perfectly clear to me whether an IEEE infinity should be
@@ -44,113 +44,113 @@
I do know about <values.h>, but the whole point of this file is that
we can't always trust that stuff to be there or to be correct.
*/
-static int MDMINEXPT = {-323};
-static char MDMINFRAC[] = "494065645841246544";
-static double ZERO = 0.0;
+static int MDMINEXPT = -323;
+static char MDMINFRAC[] = "494065645841246544";
+static double ZERO = 0.0;
-static int MDMAXEXPT = { 309};
-static char MDMAXFRAC[] = "17976931348623157";
-static double HUGE = 1.7976931348623157e308;
+static int MDMAXEXPT = 309;
+static char MDMAXFRAC[] = "17976931348623157";
+static double HUGE = 1.7976931348623157e308;
-extern double atof(const char *); /* Only called when result known to be ok */
+extern double atof(const char *); /* Only called when result known to be ok */
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
-extern int errno;
+extern int errno;
double strtod(char *str, char **ptr)
{
- int sign, scale, dotseen;
- int esign, expt;
- char *save;
- register char *sp, *dp;
- register int c;
- char *buforg, *buflim;
- char buffer[64]; /* 45-digit significant + */
- /* 13-digit exponent */
- sp = str;
- while (*sp == ' ') sp++;
- sign = 1;
- if (*sp == '-') sign -= 2, sp++;
- dotseen = 0, scale = 0;
- dp = buffer;
- *dp++ = '0'; *dp++ = '.';
- buforg = dp, buflim = buffer+48;
- for (save = sp; c = *sp; sp++)
- if (c == '.') {
- if (dotseen) break;
- dotseen++;
- } else
- if ((unsigned)(c-'0') > (unsigned)('9'-'0')) {
- break;
- } else
- if (c == '0') {
- if (dp != buforg) {
- /* This is not the first digit, so we want to keep it */
- if (dp < buflim) *dp++ = c;
- if (!dotseen) scale++;
- } else {
- /* No non-zero digits seen yet */
- /* If a . has been seen, scale must be adjusted */
- if (dotseen) scale--;
- }
- } else {
- /* This is a nonzero digit, so we want to keep it */
- if (dp < buflim) *dp++ = c;
- /* If it precedes a ., scale must be adjusted */
- if (!dotseen) scale++;
- }
- if (sp == save) {
- if (ptr) *ptr = str;
- errno = EDOM; /* what should this be? */
- return ZERO;
- }
-
- while (dp > buforg && dp[-1] == '0') --dp;
- if (dp == buforg) *dp++ = '0';
- *dp = '\0';
- /* Now the contents of buffer are
- +--+--------+-+--------+
- |0.|fraction|\|leftover|
- +--+--------+-+--------+
- ^dp points here
- where fraction begins with 0 iff it is "0", and has at most
- 45 digits in it, and leftover is at least 16 characters.
- */
- save = sp, expt = 0, esign = 1;
- do {
- c = *sp++;
- if (c != 'e' && c != 'E') break;
- c = *sp++;
- if (c == '-') esign -= 2, c = *sp++; else
- if (c == '+' /* || c == ' ' */ ) c = *sp++;
- if ((unsigned)(c-'0') > (unsigned)('9'-'0')) break;
- while (c == '0') c = *sp++;
- for (; (unsigned)(c-'0') <= (unsigned)('9'-'0'); c = *sp++)
- expt = expt*10 + c-'0';
- if (esign < 0) expt = -expt;
- save = sp-1;
- } while (0);
- if (ptr) *ptr = save;
- expt += scale;
- /* Now the number is sign*0.fraction*10**expt */
- errno = ERANGE;
- if (expt > MDMAXEXPT) {
- return HUGE*sign;
- } else
- if (expt == MDMAXEXPT) {
- if (strcmp(buforg, MDMAXFRAC) > 0) return HUGE*sign;
- } else
- if (expt < MDMINEXPT) {
- return ZERO*sign;
- } else
- if (expt == MDMINEXPT) {
- if (strcmp(buforg, MDMINFRAC) < 0) return ZERO*sign;
- }
- /* We have now established that the number can be */
- /* represented without overflow or underflow */
- (void) sprintf(dp, "E%d", expt);
- errno = 0;
- return atof(buffer)*sign;
+ int sign, scale, dotseen;
+ int esign, expt;
+ char *save;
+ register char *sp, *dp;
+ register int c;
+ char *buforg, *buflim;
+ char buffer[64]; /* 45-digit significant + */
+ /* 13-digit exponent */
+ sp = str;
+ while (*sp == ' ') sp++;
+ sign = 1;
+ if (*sp == '-') sign -= 2, sp++;
+ dotseen = 0, scale = 0;
+ dp = buffer;
+ *dp++ = '0'; *dp++ = '.';
+ buforg = dp, buflim = buffer+48;
+ for (save = sp; c = *sp; sp++)
+ if (c == '.') {
+ if (dotseen) break;
+ dotseen++;
+ } else
+ if ((unsigned)(c-'0') > (unsigned)('9'-'0')) {
+ break;
+ } else
+ if (c == '0') {
+ if (dp != buforg) {
+ /* This is not the first digit, so we want to keep it */
+ if (dp < buflim) *dp++ = c;
+ if (!dotseen) scale++;
+ } else {
+ /* No non-zero digits seen yet */
+ /* If a . has been seen, scale must be adjusted */
+ if (dotseen) scale--;
+ }
+ } else {
+ /* This is a nonzero digit, so we want to keep it */
+ if (dp < buflim) *dp++ = c;
+ /* If it precedes a ., scale must be adjusted */
+ if (!dotseen) scale++;
+ }
+ if (sp == save) {
+ if (ptr) *ptr = str;
+ errno = EDOM; /* what should this be? */
+ return ZERO;
+ }
+
+ while (dp > buforg && dp[-1] == '0') --dp;
+ if (dp == buforg) *dp++ = '0';
+ *dp = '\0';
+ /* Now the contents of buffer are
+ +--+--------+-+--------+
+ |0.|fraction|\|leftover|
+ +--+--------+-+--------+
+ ^dp points here
+ where fraction begins with 0 iff it is "0", and has at most
+ 45 digits in it, and leftover is at least 16 characters.
+ */
+ save = sp, expt = 0, esign = 1;
+ do {
+ c = *sp++;
+ if (c != 'e' && c != 'E') break;
+ c = *sp++;
+ if (c == '-') esign -= 2, c = *sp++; else
+ if (c == '+' /* || c == ' ' */ ) c = *sp++;
+ if ((unsigned)(c-'0') > (unsigned)('9'-'0')) break;
+ while (c == '0') c = *sp++;
+ for (; (unsigned)(c-'0') <= (unsigned)('9'-'0'); c = *sp++)
+ expt = expt*10 + c-'0';
+ if (esign < 0) expt = -expt;
+ save = sp-1;
+ } while (0);
+ if (ptr) *ptr = save;
+ expt += scale;
+ /* Now the number is sign*0.fraction*10**expt */
+ errno = ERANGE;
+ if (expt > MDMAXEXPT) {
+ return HUGE*sign;
+ } else
+ if (expt == MDMAXEXPT) {
+ if (strcmp(buforg, MDMAXFRAC) > 0) return HUGE*sign;
+ } else
+ if (expt < MDMINEXPT) {
+ return ZERO*sign;
+ } else
+ if (expt == MDMINEXPT) {
+ if (strcmp(buforg, MDMINFRAC) < 0) return ZERO*sign;
+ }
+ /* We have now established that the number can be */
+ /* represented without overflow or underflow */
+ (void) sprintf(dp, "E%d", expt);
+ errno = 0;
+ return atof(buffer)*sign;
}
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