From: "alexeymuranov (Alexey Muranov)" <redmine@...>
Date: 2013-07-24T18:34:13+09:00
Subject: [ruby-core:56151] [ruby-trunk - Feature #7292] Enumerable#to_h


Issue #7292 has been updated by alexeymuranov (Alexey Muranov).


I have stumbled upon a need for a method like this, to chain transformations of a hash and get a hash as a result.  Just a quick thought (please tell me if i have overlooked something): it seems to me that other "#to_?" methods are applicable to all or almost all instances of a class, whereas here the method would be applicable only to a special kind of an arrays: the ones consisting of key-value pairs.

Maybe there is no need to call it "#to_h", and it is better reserve "#to_h" for some operation applicable to all arrays?  Maybe the proposed method can be called something like "#as_hash" , "#as_h", or a different name?

[[1, 2], [3,4]].as_hash # => {1=>2, 3=> 4}
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Feature #7292: Enumerable#to_h
https://bugs.ruby-lang.org/issues/7292#change-40644

Author: marcandre (Marc-Andre Lafortune)
Status: Assigned
Priority: Low
Assignee: matz (Yukihiro Matsumoto)
Category: core
Target version: next minor


Now that #to_h is the official method for explicit conversion to Hash, we should also add

	Enumerable#to_h: Returns a hash for the yielded key-value pairs.

	  [[:name, 'Joe Smith'], [:age, 42]].to_h # => {name: 'Joe Smith', age: 42}


With the Ruby tradition of succint documentation I suggest the documentation talk about key-value pairs and there is no need to be explicit about the uninteresting cases like:

    (1..3).to_h           # => {1 => nil, 2 => nil, 3 => nil}
    [[1, 2], [1, 3]].to_h # => {1 => 3}
    [[1, 2], []].to_h     # => {1 => 2, nil => nil}

I see some reactions of people reading about the upcoming 2.0 release like this one:
http://globaldev.co.uk/2012/11/ruby-2-0-0-preview-features/#dsq-comment-body-700242476



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