From: James Edward Gray II <james@...>
Date: 2005-06-13T22:09:45+09:00
Subject: Re: finding Hash subsets based on key value

On Jun 13, 2005, at 3:55 AM, Robert Klemme wrote:

> Martin DeMello wrote:
>
>> Robert Klemme <bob.news@gmx.net> wrote:
>>
>>>
>>> IMHO we should have a general partitioning method (probably in
>>> Enumerable) that does partitioning into several buckets and not just
>>> two.  Something like this maybe:
>>>
>>> module Enumerable
>>>   def general_partition
>>>
>>
>> I like it, but not the name. partition_by, perhaps.
>>
>
> Yes, this is *much* better!

The Set class has this feature and I even like the name:

irb(main):001:0> require "set"
=> true
irb(main):002:0> langs = Set.new([:perl, :python, :ruby])
=> #<Set: {:perl, :python, :ruby}>
irb(main):003:0> langs.classify { |m| m.to_s[0, 1] }
=> {"p"=>#<Set: {:perl, :python}>, "r"=>#<Set: {:ruby}>}

James Edward Gray II