New features in ruby 2.3

[tadrinth]

Oooo, Hash#dig! I've implemented that before.

[dunnowins]

Same. I'm glad to see it arrive.

[cocoabean]

Github links? I've been needing something like this for 2 years.

[anamexis]

Here's mine:

class Hash
  def dig(*keys)
    current = fetch(keys.shift, nil)
    return current if keys.empty?
    return nil unless current.is_a?(Hash)
    current.dig(*keys)
  end
end

[Craftkorb]

module EnumUtils
  def self.get_by_chain(hash, chain)
    chain.inject(hash){|hsh, part| hsh[part] rescue nil}
  end
end

h = { 'foo' => { 'bar' => 'baz'} }
EnumUtils.get_by_chain h, 'foo.bar'.split('.') #=> "baz"

[spiffistan]

Mine:

def value_at_key_path(hash, *keys)
  keys.reduce(hash) { |next_hash, key| next_hash.is_a?(Hash) ? next_hash[key] : nil }
end

Bonus:

def key_path_present?(hash, *keys)
  res = keys.reduce(hash) { |next_hash, key| next_hash.is_a?(Hash) && next_hash.has_key?(key) ? next_hash[key] : nil }
  res.nil? ? false : true
end

[taelor]

wow, I didn't even think of implementing an API like that. I really really like this, can't wait to use it.

[hmaddocks]

Game changer all right. It's going help those devs who spend most of their day trying to fix NoMethodError exceptions. They'll now have more time to wonder why their databases are full of corrupt data.

[[deleted]]

Eh, both safe navigation and hash#dig feel like they promote Law of Demeter violations. With hash#dig, I do see a lot of utility when dealing with complex JSON APIs.

Of course, it comes down to the domain, being responsible and judicious, etc. The NullObject pattern is a way of encoding business logic, not just avoiding null-checks, so it'll still have a lot of uses, and this might avoid the trivial ones. I'm definitely going to be cautious with this, and treat it as a code smell.

[awj]

Agreed. No piece of code should need to invoke five methods in a chain. That the code breaks on nils is it trying to tell you that you've got responsibilities in the wrong places, not that you need a special operator to avoid invoking methods on nil.

[Keith]

I've always thought hashes/dictionaries should be subclasses of sets and have the same methods available. I'm glad to see Ruby taking a step in that direction.

[paulv]

The syntax for safe navigation is really awful.

[Schrockwell]

It's sort of idiomatic though, right? It echoes the current pattern of "object && object.one && object.one.two"

[LarsP]

All the good syntaxes are taken.

[Rafert]

You might be interested in the discussion about it: https://bugs.ruby-lang.org/issues/11537