From: "bitsweat (Jeremy Kemper)" <jeremy@...>
Date: 2012-11-08T06:32:04+09:00
Subject: [ruby-core:49071] [ruby-trunk - Feature #7292] Enumerable#to_h


Issue #7292 has been updated by bitsweat (Jeremy Kemper).


+1 to this.

I didn't like it at first because `#to_h` means coercion to me, and it doesn't make sense to coerce an Enumerable to a Hash. However, `Array#to_h` does seem like a good fit. Coerce this array of associated key/value pairs to a hash. Deal with edge cases in the same was as `Hash[]`.

I'd immediately change a lot of code to use this if it was available. Ending a chain of enumerable methods with `.to_h` is much nicer than "going back" to wrap it in `Hash[]`.

(Perhaps `Enumerable#to_h` could remain as a shortcut for `to_a.to_h`?)
----------------------------------------
Feature #7292: Enumerable#to_h
https://bugs.ruby-lang.org/issues/7292#change-32597

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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