From: Michael Fellinger <m.fellinger@...>
Date: 2010-04-15T20:54:58+09:00
Subject: Re: 1.9's New Methods

On Thu, Apr 15, 2010 at 8:30 PM, Ryan Davis <ryand-ruby@zenspider.com> wrote:
>
> On Apr 15, 2010, at 4:06 AM, Intransition <transfire@gmail.com> wrote:
>
>> First a big shout-out to Marc-Andre Lafortune and his <a href="http://
>> github.com/marcandre/backports">backports</a> project. Nice work.
>>
>> Now I want to ask if others have noticed all the new methods being add
>> to 1.9+? I'm quite happy about vast majority of it, but there was at
>> least one method I thought pretty peculiar. This Enumerable method:
>>
>>  def flat_map(&block)
>>    return to_enum(:flat_map) unless block_given?
>>    map(&block).flatten(1)
>>  end unless method_defined? :flat_map
>>  Backports.alias_method self, :collect_concat, :flat_map
>>
>> I am very curious to know how it was decided that a normal map
>> followed by a 1-deep flatten is common enough to warrant its own
>> method? Two in fact!
>
> i use Hash[*collection.map {...}.flatten] all the time.
>
>

Hash[[1,2,3].map{|i| [i,i*2]}]
# {1=>2, 2=>4, 3=>6}
RUBY_DESCRIPTION
# "ruby 1.9.1p378 (2010-01-10 revision 26273) [x86_64-linux]"

-- 
Michael Fellinger
CTO, The Rubyists, LLC