[ruby-dev:33506] '0_2'.to_i

String#to_i が正しく機能しないことがあります。ruby 自身の字句解釈とも
違います。たぶん、1.8 も同じです。

$ ./ruby -v -e 'p "0_2".to_i'
ruby 1.9.0 (2008-01-29 revision 0) [i386-freebsd6.2]
0

こんな感じでしょうか。


Index: bignum.c
===================================================================
--- bignum.c	(revision 15328)
+++ bignum.c	(working copy)
@@ -438,7 +438,7 @@
 	len = 2;
 	break;
       case 8:
-	if (str[0] == '0' && (str[1] == 'o'||str[1] == 'O'||str[1] == '_')) {
+	if (str[0] == '0' && (str[1] == 'o'||str[1] == 'O')) {
 	    str += 2;
 	}
       case 4: case 5: case 6: case 7:
@@ -470,7 +470,7 @@
 	break;
     }
     if (*str == '0') {		/* squeeze preceding 0s */
-	while (*++str == '0');
+	while (*++str == '0' || *str == '_');
 	if (!(c = *str) || ISSPACE(c)) --str;
     }
     c = *str;
Index: test/ruby/test_bignum.rb
===================================================================
--- test/ruby/test_bignum.rb	(revision 15328)
+++ test/ruby/test_bignum.rb	(working copy)
@@ -147,6 +147,9 @@
     assert_raise(ArgumentError) { Integer("1__") }
     assert_raise(ArgumentError) { Integer("1_0 x") }
     assert_equal(T31P, "1111111111111111111111111111111".to_i(2))
+    assert_equal(0_2, '0_2'.to_i)
+    assert_equal(00_2, '00_2'.to_i)
+    assert_equal(00_02, '00_02'.to_i)
   end
 
   def test_to_s2