From: "Haase, Konstantin" <Konstantin.Haase@...>
Date: 2011-11-01T09:33:55+09:00
Subject: [ruby-core:40591] Re: [ruby-trunk - Feature #5531][Open] deep_value for dealing with nested hashes

Never mind, got it.

On Oct 31, 2011, at 17:32 , Haase, Konstantin wrote:

> What's the difference (usability wise) between
> 
> 	hash[:foo][:bar]
> 
> and
> 
> 	hash.dv(:foo, :bar)
> 
> Konstantin
> 
> On Oct 31, 2011, at 16:52 , Kyle Peyton wrote:
> 
>> 
>> Issue #5531 has been reported by Kyle Peyton.
>> 
>> ----------------------------------------
>> Feature #5531: deep_value for dealing with nested hashes
>> http://redmine.ruby-lang.org/issues/5531
>> 
>> Author: Kyle Peyton
>> Status: Open
>> Priority: Normal
>> Assignee: 
>> Category: 
>> Target version: 
>> 
>> 
>> This feature request stems from dealing with nested hashes, like the params from a request often dealt with in web frameworks.
>> 
>> Conditional code often needs to be written with multiple logical ANDs in order to achieve what this simple function can:
>> 
>> class Hash
>> def deep_value(*ks)
>>   if ks.size == 1
>>     return self[ks.shift]
>>   else
>>     val = ks.shift
>>     return (self[val].is_a?(Hash) ? self[val].deep_value(*ks) : nil)
>>   end
>> end
>> 
>> alias dv deep_value
>> end
>> 
>> 
>> deep_value (dv) will simply recurse over a hash given a set of indexes and return the value at the end.
>> 
>> Example:
>> 
>>> foo = {:bar => {:baz => 'blah'}}
>>> foo.dv(:bar, :baz)
>> -> 'blah'
>>> foo.dv(:cats)
>> -> nil
>> 
>> 
>> 
>> -- 
>> http://redmine.ruby-lang.org
>> 
> 
>