From: Alva <alv@...>
Date: 2001-09-17T18:07:12+09:00
Subject: [ruby-talk:21279] Re: Exceptions and Ruby

On Sun, 16 Sep 2001 17:40:44 +0200, you wrote:

>[Alva]
>> Why accessing out-of-range index in Array or not existing
>> key in Hash doesn't yield exception? This is definately
>> programming error, so shouldn't the interpretar aid me
>> in finding it? Now you probably get something like NameError
>> sooner or later, when you'll try to invoke method on nil, but this
>> isn't half that descriptive as say IndexError.
>
>It is more convenient, allowing you to write, for example,
>
>	hash[x] ||= 1
>
>instead of
>
>	hash[x] = 1 if not hash.has_key?(x)
>
Ugh, you got me. What does the operator ||= do?
Couldn't find it in manual.

>If you prefer "safer" programming you can always use fetch or change the
>implementation of []
>
>	class Hash
>		def [](x)
>			fetch(x)
>		end
>	end
>
Great, thanks

Pozdrawiam, Tomek 'Alva' Wr�blewski


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