* error.c: RDoc for subclasses of Exception. [ruby-core:28394]

* cont.c: ditto

* enumerator.c: ditto

* io.c: ditto

* math.c: ditto

* numeric.c: ditto

* proc.c: ditto

* re.c: ditto

* thread.c: ditto

* transcode.c: ditto. Thanks to Run Paint for some of the documentation.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_2@27673 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

re.c

@@ -3448,6 +3448,18 @@ re_warn(const char *s)
     rb_warn("%s", s);
 }
 
+/*
+ *  Document-class: RegexpError
+ *
+ *  Raised when given an invalid regexp expression.
+ *
+ *     Regexp.new("?")
+ *
+ *  <em>raises the exception:</em>
+ *
+ *     RegexpError: target of repeat operator is not specified: /?/
+ */
+
 /*
  *  Document-class: Regexp
  *