Adding Hash#compact and Hash#compact! methods

[tinogomes]

Example:

hash = { a: true, b: false, c: nil }
hash.compact # => { a: true, b: false }

Benchmark for better solution:

https://gist.github.com/tinogomes/8332883

[rafaelfranca]

Not sure.

The name seems awkward to me. compact means remove the key-value pair with nil as key, or remove the key-value pair with nil as value?

In my the snippet below is clear about the intention.

my_hash.reject! { |_, v| v.nil? }

Also, I had a hard time thinking in which cases I'd use this code, and I could not see any usage in regular application.

[tinogomes]

@rafaelfranca I named as compact inspired by the behavior of Array#compact that is to remove the nil values. We can rename? I do not know a better name right now.

For my usage:

    def standard_button(text, title=text, disabled_text=nil, class_style='submitForward')
      submit_options = :title => title, :class => class_style
      submit_options['data-disable-with'] = disabled_text unless disabled_text.nil?

      submit_tag text, submit_options
   end

instead:

    def standard_button(text, title=text, disabled_text=nil, class_style='submitForward')
      submit_tag text, {:title => title, :class => class_style, 'data-disable-with' => disabled_text}.compact
    end

yes, I can use reject {|_,v| v.nil? }, but repeating this expression for all my codebase, I feel something is wrong.

[rafaelfranca]

Interesting usage. I think we have some code like this even inside Rails.

I'll delegate to @dhh who is better naming things than I 😄

[carlosantoniodasilva]

As a side note, given your use case, Rails has you covered:

<%= submit_tag 'zomg', :title => 'title', :class => 'class_style', 'data-disable-with' => nil %>

Would output:

<input class="class_style" name="commit" title="title" type="submit" value="zomg" />

Rails already ignores attributes containing nil values, not generating them on the output html.

[tinogomes]

@carlosantoniodasilva

Nice to know that Rails already ignore nil values for Helpers.

[dhh]

I'm sympathetic to this idea. I even think the name parity with Array#compact makes sense. I do remember writing similar code in the past. So 👍 on name and method from me.

[rafaelfranca]

Use Ruby 1.9 syntax

[tinogomes]

👍

[rafaelfranca]

Great! Lets get this in.

@tinogomes we need to upgrade the active_support guides and we need a CHANGELOG entry.

[carlosantoniodasilva]

You should be able to use dup.compact!, right?

[tinogomes]

👍

[tinogomes]

@carlosantoniodasilva @rafaelfranca active_support guides and CHANGELOG updated and all your suggestions done!

[egilburg]

put this in alphabetical order with other requires

[tinogomes]

👍

[tinogomes]

@egilburg all done!

[vipulnsward]

return a Hash

[tinogomes]

👍

[vipulnsward]

@tinogomes you'll need to squash your commits.

[vipulnsward]

why select here and reject below? We can have the same implementation at both the places?

[tinogomes]

Benchmark for better solution:

https://gist.github.com/tinogomes/8332883

[tinogomes]

squashed!

[rafaelfranca]

❤️ 💚 💙 💛 💜

[tinogomes]

👍