From: Luis D Casillas <casillas@...18.Stanford.EDU>
Date: 2004-03-30T18:54:28+09:00
Subject: Re: Surprise with Hash#new

In article <dV9ac.47224$li5.33643@pd7tw3no>, Andrew Johnson wrote:
>  On Tue, 30 Mar 2004 07:28:40 +0000 (UTC), Luis D Casillas
> <casillas@no_spam.Stanford.EDU> wrote:
> 
>> PS I ended up not needing that data structure, but after seeing my
>> mistake I managed to get the behavior I wanted this way:
> 
> Alternatively, Hash.new can take a block to generate default values:
> 
>   @seen = Hash.new {|h,k| h[k] = []}

Ah.  This is good.

-- 
Luis Casillas
Department of Linguistics
Stanford University
http://www.stanford.edu/~casillas/

"This fence is here for your protection.  Do not approach or try to
cross, or you will be shot."
-- Text of sign on US-installed barbed wire fence around village of 
   Abu Hishma, Iraq.  (NY Times, Dec. 7, 2003)