From: "trans (Thomas Sawyer)" <transfire@...>
Date: 2012-07-24T01:20:44+09:00
Subject: [ruby-core:46679] [ruby-trunk - Feature #6414] Destructuring Assignment


Issue #6414 has been updated by trans (Thomas Sawyer).


So this is a shortcut for?

  name, last = john.values_at(:name, :last)

If so, long ago it was suggested Hash#[] support multiple keys:

  name, last = john[[:name, :last]]

Not as short as `{name, last} = john`, but not quite as esoteric either.

If assigning from an array can work, eg.

  john = ['John', 'Smith']
  name, last = john

Why not hash? So, just

  john = {:name=>'John', :last=>'Smith'}
  name, last = john


----------------------------------------
Feature #6414: Destructuring Assignment 
https://bugs.ruby-lang.org/issues/6414#change-28345

Author: edtsech (Edward Tsech)
Status: Assigned
Priority: Normal
Assignee: matz (Yukihiro Matsumoto)
Category: core
Target version: 2.0.0


I mean:

john = {name: "John", last: "Smith"}
{name, last} = john # extract value by key from the hash and set to local variable with same name
name # => "John"
last # -> "Smith"

Useful for ex. for  "options" hashes:
def select(options={})
  {only, except} = options
  ...
end

As extra part of this feature can be hash constructing in this way:

name = "John"
last    = "Smith"
find({name, last}) # equals to => find({name: "John", last: "Smith"})

I think both really nice to have in Ruby.
Thanks.


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