From: ts <decoux@...>
Date: 2002-01-01T21:16:05+09:00
Subject: [ruby-talk:29947] Re: A Bug or something else?

>>>>> "m" ==   <mengx@nielsenmedia.com> writes:

m> It works. Thanks.  But would it have any side effects? I wonder why "private"
m> did not disable the outside access to "nil". I asked a question before

 Well, in ruby a private method is a method that can be called only in a
 function form (i.e. it can have only self as a receiver). Here you are in
 a special where ruby want to convert a value to a string, and in this case
 it can call any methods (public, private, ...)

m> about the reasoning for the existence of methods for "nil", such as "to_a",
m> "to_i", "to_s". Can an exception  be raised for this scenario and the one
m> below?

m> a = nil

m> a == 1    => false  (even after the undef)

 Well here you have written something like
   
   a.== 1

 this mean that if you undef #== for NilClass it will work

pigeon% ruby
class NilClass
   undef ==
end
a = nil
a == 1
^D
-:5: undefined method `==' for nil (NameError)
pigeon%

 it's still work with

  1 == a

 but this is a special case and will not do what you want with (for example)

  [] == a


m> "a=nil" may be seen as creating a variable but no real value assigned yet.

 For me, this case is more `undef' than `nil' 

m> Should the "a == 1" be invalid?

 not for me


Guy Decoux