From: "S.Volkov" <svolkov@...>
Date: 2006-03-11T14:58:43+09:00
Subject: String subclass method returns subclass - bug or feature?

Could you please explain me why String instance methods return subclass,
and MyStr#to_s returns String, not the receiver as specified?

# here is the test code
$ cat tStringSubClass.rb
class MyStr < String
    def rest
        self[1..-1]
    end
end
ms = MyStr.new('ABC')
puts \
'I got ' + ms.class.name,
'Expect String, get:',
    ms.rest.class,
    ms.downcase.class,
    ms.succ.class,
    ms[1..-1].class,
    ms.split(//).map{ |s| s.class },
'Expect MyStr, get:',
    ms.to_s.class,
    ms.to_str.class
# and here is the result
$ ruby tStringSubClass.rb
I got MyStr
Expect String, get:
MyStr
MyStr
MyStr
MyStr
MyStr
MyStr
MyStr
Expect MyStr, get:
String
String
-------

thanks
brs
Sergey