Issue #14546 has been updated by janosch-x (Janosch Mller).


duerst (Martin Drst) wrote:
> it would be a bad idea to use a bang method in a context (such as delete) where it can be very easily mistaken as a mutating version (and by opposition, the non-bang method would be misunderstood as a non-mutating version).

I'm not sure that point holds in such a general way. E.g. I've never seen `ActiveRecord::Base#destroy` being mistaken for a non-destructive version of `#destroy!`.

In my opinion, the main reason why `#delete!` feels confusing is that there are already `#delete` and `#delete!` implementations in Ruby that differ by destructiveness, e.g. on String. That is an unfortunate inconsistency when compared to `Hash#delete`.

Maybe something like `Hash#yank` could be introduced as an alias for delete and `#yank!` as a whiny version. That could both serve the need stated by the OP and also undercut this existing inconsistency.

----------------------------------------
Feature #14546: Hash#delete!
https://bugs.ruby-lang.org/issues/14546#change-72305

* Author: rringler (Ryan Ringler)
* Status: Open
* Priority: Normal
* Assignee: matz (Yukihiro Matsumoto)
* Target version: 
----------------------------------------
Hash#delete currently returns nil if a given key is not found in the hash. It would be nice to have a way to check that the key was present in the hash. This can be accomplished with with a block, but it would be nice to have some sugar for this.

~~~ ruby
{ a: 'a' }.delete(:b)                                                  # => nil
{ a: 'a' }.delete(:b) { |key| raise KeyError, "key not found #{key}" } # => KeyError (key not found: b)
~~~

I'd like to propose a Hash#delete! method:

~~~ruby
{ a: 'a' }.delete!(:a) # => 'a'
{ a: 'a' }.delete!(:b) # => KeyError (key not found: :b)
~~~


---Files--------------------------------
hash_delete_bang.patch (2.37 KB)


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