diff options
Diffstat (limited to 'numeric.c')
-rw-r--r-- | numeric.c | 57 |
1 files changed, 42 insertions, 15 deletions
@@ -558,35 +558,62 @@ rb_float_new(double d) static VALUE flo_to_s(VALUE flt) { + char *ruby_dtoa(double d_, int mode, int ndigits, int *decpt, int *sign, char **rve); enum {decimal_mant = DBL_MANT_DIG-DBL_DIG}; enum {float_dig = DBL_DIG+1}; char buf[float_dig + (decimal_mant + CHAR_BIT - 1) / CHAR_BIT + 10]; double value = RFLOAT_VALUE(flt); + VALUE s; char *p, *e; + int sign, decpt, digs; if (isinf(value)) return rb_usascii_str_new2(value < 0 ? "-Infinity" : "Infinity"); else if (isnan(value)) return rb_usascii_str_new2("NaN"); -# define FLOFMT(buf, size, fmt, prec, val) snprintf(buf, size, fmt, prec, val), \ - (void)((atof(buf) == val) || snprintf(buf, size, fmt, (prec)+1, val)) - - FLOFMT(buf, sizeof(buf), "%#.*g", float_dig, value); /* ensure to print decimal point */ - if (!(e = strchr(buf, 'e'))) { - e = buf + strlen(buf); + p = ruby_dtoa(value, 0, 0, &decpt, &sign, &e); + s = sign ? rb_usascii_str_new_cstr("-") : rb_usascii_str_new(0, 0); + if ((digs = (int)(e - p)) >= (int)sizeof(buf)) digs = (int)sizeof(buf) - 1; + memcpy(buf, p, digs); + xfree(p); + if (decpt > 0) { + if (decpt < digs) { + memmove(buf + decpt + 1, buf + decpt, digs - decpt); + buf[decpt] = '.'; + rb_str_cat(s, buf, digs + 1); + } + else if (decpt - digs < float_dig) { + rb_str_cat(s, buf, digs); + rb_str_cat(s, ".0", 2); + } + else { + goto exp; + } } - if (!ISDIGIT(e[-1])) { /* reformat if ended with decimal point (ex 111111111111111.) */ - FLOFMT(buf, sizeof(buf), "%#.*e", float_dig - 1, value); - if (!(e = strchr(buf, 'e'))) { - e = buf + strlen(buf); + else if (decpt > -4) { + long len; + char *ptr; + rb_str_cat(s, "0.", 2); + rb_str_resize(s, (len = RSTRING_LEN(s)) - decpt + digs); + ptr = RSTRING_PTR(s); + memset(ptr += len, '0', -decpt); + memcpy(ptr -= decpt, buf, digs); + } + else { + exp: + if (digs > 1) { + memmove(buf + 2, buf + 1, digs - 1); + } + else { + buf[2] = '0'; + digs++; } + buf[1] = '.'; + rb_str_cat(s, buf, digs + 1); + rb_str_catf(s, "e%+d", decpt - 1); } - p = e; - while (p[-1]=='0' && ISDIGIT(p[-2])) - p--; - memmove(p, e, strlen(e)+1); - return rb_usascii_str_new2(buf); + return s; } /* |