From: "mame (Yusuke Endoh)" <mame@...>
Date: 2012-11-20T23:23:54+09:00
Subject: [ruby-core:49750] [ruby-trunk - Feature #6847][Assigned] Hash#extract


Issue #6847 has been updated by mame (Yusuke Endoh).

Status changed from Open to Assigned
Assignee set to matz (Yukihiro Matsumoto)
Target version set to next minor


----------------------------------------
Feature #6847: Hash#extract
https://bugs.ruby-lang.org/issues/6847#change-33329

Author: citizen428 (Michael Kohl)
Status: Assigned
Priority: Normal
Assignee: matz (Yukihiro Matsumoto)
Category: core
Target version: next minor


I often need a method to extract "subhashes" from hashes. I often monkey-patched this into hash and found "extract" to be a good name for the method. Afterwards I found out that there actually is a mutating method called "extract!" in ActiveSupport, so I guess the name is kinda established. Here's the Ruby version from my private extension library, if there's any interest in this I would try to re-implement it in C:

class Hash
  def extract(*ks)
    existing = keys & ks
    Hash[existing.zip(values_at(*existing))]
  end
end


-- 
http://bugs.ruby-lang.org/