strtod.c: new public domain implementation of `strtod`; ref
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 as well.
MODIFY
src/string.c
src/string.c
@@ -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

ADD
src/strtod.c
+#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

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.