Feature #21545
Updated by cb341 (Daniel Bengl) about 10 hours ago
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
```
_I initially proposed this in Ruby core (PR #14203) and even implemented it in C, but later realized that if this gets introduced at all it probably makes more sense to have it in ActiveSupport rather than in core Ruby._
**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