From: "nobu (Nobuyoshi Nakada) via ruby-core" <ruby-core@...>
Date: 2025-09-24T01:50:28+00:00
Subject: [ruby-core:123321] [Ruby Feature#21615] Introduce `Array#values`

Issue #21615 has been updated by nobu (Nobuyoshi Nakada).


matheusrich (Matheus Richard) wrote:
> Following the **Principle of Least Surprise**, users may reasonably expect `Array#values` to exist because:

"PoLS" is a word not to say at a proposal.
That word is negative to convince us.
We are not sure who started to say the word , but Ruby itself hasn't advertised it.

> With `Array#values`:
> 
> ```ruby
> def normalize_records(input)
>   input.values.each do |item|
>     do_stuff_with_item(item)
>   end
> end
> ```

Why not to introduce `Array#each_value`?

----------------------------------------
Feature #21615: Introduce `Array#values`
https://bugs.ruby-lang.org/issues/21615#change-114685

* Author: matheusrich (Matheus Richard)
* Status: Open
----------------------------------------
## Motivation

In Ruby code, it's common to accept arrays and hashes and treat them uniformly as collections of values. `Hash` exposes `#values`, but `Array` does not, which pushes developers toward `is_a?`/`respond_to?` branching.

Following the **Principle of Least Surprise**, users may reasonably expect `Array#values` to exist because:

* Both `Array` **and** `Hash` already implement `#values_at`.
* `Hash` implements `#values` but `Array` does not.

### Example

Today:

```ruby
def normalize_records(input)
  items = input.respond_to?(:values) ? input.values : input

  items.each do |item|
    do_stuff_with_item(item)
  end
end
```

With `Array#values`:

```ruby
def normalize_records(input)
  input.values.each do |item|
    do_stuff_with_item(item)
  end
end
```

## Proposal

Add `Array#values`, returning `self`. Implementation could simply alias to `itself`:

```ruby
class Array
  alias_method :values, :itself
end
```

This yields a uniform interface for `Array` and `Hash` values without type checks.

### Alternatives considered

* `Enumerable#values`: defaulting to `to_a`, but I found it too broad of a change.
* `Array#each_value`: redundant as `Array#each` already covers iteration.


Patch: https://github.com/ruby/ruby/pull/14641



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