Rails Ruby on Rails → 2.x

Comments and changes to this ticket

• 

  Repository July 17th, 2008 @ 01:28 AM

  • State changed from “new” to “resolved”

  (from [396f9df8916b71f83aad8d56559cf55fc8501679]) Hash#slice supports an array of keys [#613 state:resolved]

  Signed-off-by: Joshua Peek

  http://github.com/rails/rails/co...

• You flagged this item as spam.
  

  MatthewRudy July 17th, 2008 @ 01:19 PM

  reiterating,

  this is bad.

  if you want to pass it an array,

  you should be able to pass it an array,

  if you want to splat it,

  splat it

  hash.slice(*[:a,:b]) if you mean slice(:a, :b)

  or hash.slice([:a,:b]) if that's a key

• You flagged this item as spam.
  

  MatthewRudy July 17th, 2008 @ 01:23 PM

  and here's a perversion of the attached test.

  def test_slice_with_array_keys
    original = { :a => 'x', :b => 'y', :c => 10, [:a, :b] => "an array key" }
    expected = { [:a, :b] => "an array key", :c => 10 }
  
    # Should return a new hash with only the given keys, when given an array as a key.
    assert_equal expected, original.slice([:a, :b], :c)
    assert_not_equal expected, original
  
    # Should replace the hash with only the given keys, when given an array of keys.
    assert_equal expected, original.slice!([:a, :b], :c)
    assert_equal expected, original
  end
  

• You flagged this item as spam.
  

  MatthewRudy July 17th, 2008 @ 01:26 PM

  def test_slice_with_splatted_keys
    original = { :a => 'x', :b => 'y', :c => 10, [:a, :b] => "an array key" }
    expected = { :a => 'x', :b => "y" }
  
    # Should grab each of the splatted keys.
    assert_equal expected, original.slice(*[:a, :b])
  end
  

• You flagged this item as spam.
  

  MatthewRudy July 17th, 2008 @ 02:01 PM

  here's a patch to add the above tests

• You flagged this item as spam.
  

  ronin-17112 (at lighthouseapp) July 17th, 2008 @ 02:50 PM

  MatthewRudy,

  You are correct sir. I didn't realize a hash could have a key that was an array. I don't see a way to clarify the intentions of the method's user based on the current footprint of the method. I suppose we could just clean up the docs a bit to point out that you can use the *splat to pass an array that you don't want used for a single hash key?

• You flagged this item as spam.
  

  MatthewRudy July 17th, 2008 @ 03:09 PM

  yeah.

  here's a patch with the tests I added earlier

  and documentation on that specific use.

        # If you have an array of keys you want to limit to, you should splat them:
        #
        #   valid_keys = [:mass, :velocity, :time]
        #   search(options.slice(*valid_keys))
  

  • test_and_document_hash_slice_with_array_keys.patch 2.7 KB
• 

  Repository July 17th, 2008 @ 03:38 PM

  (from [b3a2ee7b87a6b2a4c6ff086644f40a472a676b65]) Revert "Hash#slice supports an array of keys [#613 state:resolved]"

  This reverts commit 396f9df8916b71f83aad8d56559cf55fc8501679.

  http://github.com/rails/rails/co...