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author | nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2009-03-05 09:36:39 +0000 |
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committer | nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2009-03-05 09:36:39 +0000 |
commit | 9b52ae2e6491bb5d6c59e1799449f6268baf6f89 (patch) | |
tree | a3020e451c67ff06e2b90ad94402e9fc03e2dac1 /numeric.c | |
parent | e691ba3baca5883a052d062df7c5d671c384ed0c (diff) | |
download | ruby-9b52ae2e6491bb5d6c59e1799449f6268baf6f89.tar.gz |
* numeric.c (flo_to_s): keeps enough precision for round trip.
[ruby-core:22325]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@22783 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'numeric.c')
-rw-r--r-- | numeric.c | 8 |
1 files changed, 5 insertions, 3 deletions
@@ -521,7 +521,9 @@ rb_float_new(double d) static VALUE flo_to_s(VALUE flt) { - char buf[32]; + enum {decimal_mant = DBL_MANT_DIG-DBL_DIG}; + enum {float_dig = DBL_DIG+2}; + char buf[float_dig + (decimal_mant + CHAR_BIT - 1) / CHAR_BIT + 10]; double value = RFLOAT_VALUE(flt); char *p, *e; @@ -530,12 +532,12 @@ flo_to_s(VALUE flt) else if(isnan(value)) return rb_usascii_str_new2("NaN"); - snprintf(buf, sizeof(buf), "%#.15g", value); /* ensure to print decimal point */ + snprintf(buf, sizeof(buf), "%#.*g", float_dig, value); /* ensure to print decimal point */ if (!(e = strchr(buf, 'e'))) { e = buf + strlen(buf); } if (!ISDIGIT(e[-1])) { /* reformat if ended with decimal point (ex 111111111111111.) */ - snprintf(buf, sizeof(buf), "%#.14e", value); + snprintf(buf, sizeof(buf), "%#.*e", float_dig - 1, value); if (!(e = strchr(buf, 'e'))) { e = buf + strlen(buf); } |