[ruby-core:77827] [Ruby trunk Feature#5531][Closed] deep_value for dealing with nested hashes

Issue #5531 has been updated by Shyouhei Urabe.

Status changed from Assigned to Closed

Dan Erikson wrote:
> I believe this has recently been implemented as `Hash#dig`.

Indeed.  Closing peacefully.

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Feature #5531: deep_value for dealing with nested hashes
https://bugs.ruby-lang.org/issues/5531#change-61133

* Author: Kyle Peyton
* Status: Closed
* Priority: Normal
* Assignee: Yukihiro Matsumoto
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This feature request stems from dealing with nested hashes, like the params from a request often dealt with in web frameworks.

Conditional code often needs to be written with multiple logical ANDs in order to achieve what this simple function can:

class Hash
  def deep_value(*ks)
    if ks.size == 1
      return self[ks.shift]
    else
      val = ks.shift
      return (self[val].is_a?(Hash) ? self[val].deep_value(*ks) : nil)
    end
  end
  
  alias dv deep_value
end


deep_value (dv) will simply recurse over a hash given a set of indexes and return the value at the end.

Example:

> foo = {:bar => {:baz => 'blah'}}
> foo.dv(:bar, :baz)
-> 'blah'
> foo.dv(:cats)
-> nil




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