From: gotoken@... (GOTO Kentaro)
Date: 2001-03-07T05:45:15+09:00
Subject: [ruby-talk:12177] Re: (long) Re: hash.invert loses data if equal values exist - is this the right behaviour?

In message "[ruby-talk:12158] Re: (long) Re: hash.invert loses data if equal values exist - is this the right behaviour?"
    on 01/03/07, Dave Thomas <Dave@PragmaticProgrammer.com> writes:
>As an artificial example:
>
>  e_2_j = { "one" => "ichi", "two" => "ni", "three" => "san" }
>  j_2_e = e_2_j.invert
>
>Of course this breaks down at "shi" => "four", "yon" => "four", but
>there are many true one-to-one mappings where .invert can be useful.

Yes, it could be useful sometime.  Thank you. 

But I feel a little danger because Hash does not have any checking
mechanism to detect multiple values.  At least it should be documented
in the reference manual.

-- Gotoken