Issue #12282 has been updated by Tsuyoshi Sawada.


Nobuyoshi Nakada wrote:
> It raises a `TypeError`.

I think it is a typographical error of

~~~ruby
places.dig  :countries, :ontario # => nil
places.dig! :countries, :ontario # => KeyError: Key not found: :ontario
~~~

----------------------------------------
Feature #12282: Hash#dig! for repeated applications of Hash#fetch
https://bugs.ruby-lang.org/issues/12282#change-58078

* Author: Robb Shecter
* Status: Open
* Priority: Normal
* Assignee: 
----------------------------------------
A new feature for your consideration: #dig! which is to #fetch as #dig is to #[]. For me and maybe many others, Hash#fetch is used much more than Hash#[]. And traversing multiple fetches isn't very convenient nor Ruby-like, e.g.: places.fetch(:countries).fetch(:canada).fetch(ontario).

Here's how it would work:

~~~ruby
places = { countries: { canada: true } }

places.dig  :countries, :canada  # => true
places.dig! :countries, :canada  # => true

places.dig  :countries, :canada, :ontario  # => nil
places.dig! :countries, :canada, :ontario  # => KeyError: Key not found: :ontario

~~~


Here's an implementation and tests: https://gist.github.com/dogweather/819ccdb41c9db0514c163cfdb1c528e2



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