From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2009-02-07T19:09:33+09:00
Subject: Re: Special Hash Constructors

On Sat, Feb 7, 2009 at 5:34 AM, Simon Krahnke <overlord@gmx.li> wrote:
> * Robert Klemme <shortcutter@googlemail.com> (18:05) schrieb:

>> def Hash.with_hashes
>>   new {|h,k| h[k] = Hash.new(&h.default_proc)}
>> end
>
> I'm too tired for that. Does that create Hash with a default proc that
> is the same as the one you specify right there?

Yes, it achieves having infinitely nested hashes:

irb(main):001:0> def Hash.with_hashes
irb(main):002:1> new {|h,k| h[k] = Hash.new(&h.default_proc)}
irb(main):003:1> end
=> nil
irb(main):004:0> h = Hash.with_hashes
=> {}
irb(main):005:0> h[1][2][3] = true
=> true
irb(main):006:0> h
=> {1=>{2=>{3=>true}}}

I agree that it would be nice to have them in the standard library,
but maybe Hash.of_hashes and Hash.of_arrays would be better names?

Jesus.