From: "Luke A. Kanies" <luke@...>
Date: 2004-01-11T00:25:49+09:00
Subject: Question on hashes and init block

Hi all,

I'm using the trick someone mentioned here a few weeks ago to attach a
block to a hash so I can return an error if someone tries to access a
key which does not exist:

a = Hash.new { |key,value|
	raise "Missing key [#{key}] => [#{value}]"
}
puts a["yay"]

Strangely, this results in the following:

missing [] => [yay]
nil

In other words, I try to access a key, and the attached block complains
that that key doesn't exist, but it treats it as a value instead.

I can work around this, obviously, because it's consistent, but can
someone explain this to me?  Is this behaviour going to change?  Am I just
not understanding what is going on?

Thanks,
Luke

-- 
"What's the good of having mastery over cosmic balance and knowing the
secrets of fate if you can't blow something up?"
                -- Terry Pratchett, "Reaper Man"