From: Niklas Frykholm <r2d2@...>
Date: 2001-09-17T00:40:17+09:00
Subject: [ruby-talk:21266] Re: Exceptions and Ruby

[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)

If you prefer "safer" programming you can always use fetch or change the
implementation of []

	class Hash
		def [](x)
			fetch(x)
		end
	end

// Niklas