From: ES <ruby-ml@...>
Date: 2005-05-09T05:32:53+09:00
Subject: Re: RCR 303: nil should accept missing methods and return nil


Le 8/5/2005, "John Carter" <john.carter@tait.co.nz> a �crit:
>On Sat, 7 May 2005, Austin Ziegler wrote:
>
>> You may, however, be left with incorrect output.
>>
>>  "\n#{@oid} 0 obj\n<</Type /Page /Parent #{@owner.oid} 0 R >>"
>>
>> If @owner is nil, then using your proposal I will get:
>>
>>  234 0 obj
>>  <</Type /Page /Parent 0 R >>
>
>Hmm. Interesting.
>
>Hard real, live, data.
>
>I like it.
>
>Let's look at it a bit more closely.
>
>How did the nil get into @owner? Would it have been picked up by -w?
>Was it placed there yourself in the meaning "uninitialised" or in the
>meaning "no thing here"? By what route did it arrive?
>
>Given my new proposal of having an uninitialised vs nothing
>types of nil?
>
>Could we design things in a way that would resolve your
>issue?

Well, one could redesign so that nil is never returned from
any method at all for any purpose. While a valid suggestion
as such, it is sort of moot as far as the merits or your
original proposal go.

>John Carter

E

--
template<typename duck>
void quack(duck& d) { d.quack(); }