[前][次][番号順一覧][スレッド一覧]

ruby-changes:15814

From: nobu <ko1@a...>
Date: Wed, 12 May 2010 10:57:27 +0900 (JST)
Subject: [ruby-changes:15814] Ruby:r27745 (trunk): * numeric.c (flo_to_s): make minimum string representation.

nobu	2010-05-12 10:57:08 +0900 (Wed, 12 May 2010)

  New Revision: 27745

  http://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=rev&revision=27745

  Log:
    * numeric.c (flo_to_s): make minimum string representation.
      [ruby-core:30145]

  Modified files:
    trunk/ChangeLog
    trunk/numeric.c
    trunk/test/ruby/test_float.rb

Index: ChangeLog
===================================================================
--- ChangeLog	(revision 27744)
+++ ChangeLog	(revision 27745)
@@ -1,3 +1,8 @@
+Wed May 12 10:57:04 2010  Nobuyoshi Nakada  <nobu@r...>
+
+	* numeric.c (flo_to_s): make minimum string representation.
+	  [ruby-core:30145]
+
 Wed May 12 09:21:05 2010  NARUSE, Yui  <naruse@r...>
 
 	* re.c (rb_reg_initialize_m): fix wrong index for the lang
Index: numeric.c
===================================================================
--- numeric.c	(revision 27744)
+++ numeric.c	(revision 27745)
@@ -558,35 +558,62 @@
 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;
 }
 
 /*
Index: test/ruby/test_float.rb
===================================================================
--- test/ruby/test_float.rb	(revision 27744)
+++ test/ruby/test_float.rb	(revision 27745)
@@ -136,6 +136,13 @@
     assert_equal("NaN", (inf / inf).to_s)
 
     assert_equal("1.0e+18", 1000_00000_00000_00000.0.to_s)
+
+    bug3273 = '[ruby-core:30145]'
+    [0.21611564636388508, 0.56].each do |f|
+      s = f.to_s
+      assert_equal(f, s.to_f, bug3273)
+      assert_not_equal(f, s.chop.to_f, bug3273)
+    end
   end
 
   def test_coerce

--
ML: ruby-changes@q...
Info: http://www.atdot.net/~ko1/quickml/

[前][次][番号順一覧][スレッド一覧]