[ruby-core:122969] [Ruby Feature#21545] `#try_dig`: a dig that returns early if it cannot dig deeper

Issue #21545 has been reported by cb341 (Daniel Bengl).

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Feature #21545: `#try_dig`: a dig that returns early if it cannot dig deeper
https://bugs.ruby-lang.org/issues/21545

* Author: cb341 (Daniel Bengl)
* Status: Open
----------------------------------------
Ruby offers `dig` for traversing nested hashes and arrays. It is strict and will raise if an intermediary object does not support `dig`. In many cases we only want to attempt the lookup and return `nil` if it cannot be followed, without caring about the exact reason.

**Example:**

```rb
{ a: "foo" }.dig(:a, :b)
# TypeError: String does not have #dig method

{ a: "foo" }.try_dig(:a, :b)
# => nil
```

This is especially useful when dealing with data from APIs or other inconsistent sources:

```rb
api_response = { status: "ok" }
api_response.try_dig(:status, :code) # => nil

api_response = { status: { code: 200 } }
api_response.try_dig(:status, :code) # => 200
```

The name `try_dig` makes it clear that it behaves like `dig` but will never raise for structural mismatches.  
It complements `dig` and the proposed `dig!` ([#12282](https://bugs.ruby-lang.org/issues/12282), [#15563](https://bugs.ruby-lang.org/issues/15563)) by covering the tolerant lookup case.

A possible sketch:

```rb
class Object
  def try_dig(*path)
    current = self
    path.each do |key|
      return nil unless current.respond_to?(:dig)
      begin
        current = current.dig(key)
      rescue StandardError
        return nil
      end
    end
    current
  end
end
```

**Advantages**
  - Simplifies tolerant lookups without repetitive rescue logic  
  - Clear intent when the value is optional  
  - Useful for working with inconsistent or partially known data structures  
  - Complements `dig` and potential `dig!` by covering the tolerant case  

**Disatvantages**
  - May hide structural issues that should be noticed during development  




-- 
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