From: ara.t.howard@...
Date: 2006-07-13T06:27:33+09:00
Subject: Re: multiple level hash assignment equivalence to perl

On Thu, 13 Jul 2006, Joel VanderWerf wrote:

> don mc wrote:
>> Is there a succinct way in ruby to do a multiple level hash assignement? I 
>> am more
>> used to perl, which you can do something like
>> 
>> 
>> $hp->{level1}->{level2} = 3
>> 
>> even if the first and second level had never existed below.
>
> There's an autovivification trick, using the default proc of a hash (see ri 
> default_proc):
>
> irb(main):002:0> pr = proc {|h,k| h[k]=Hash.new(&pr) }
> => #<Proc:0x02c15618@(irb):2>
> irb(main):003:0> h = Hash.new(&pr)
                                  ^^
                                  ^^

nice!  my approach is slightly more verbose.

-a
-- 
suffering increases your inner strength.  also, the wishing for suffering
makes the suffering disappear.
- h.h. the 14th dali lama