[ruby-core:90985] [Ruby trunk Feature#14444] MatchData: alias for #[]

Issue #14444 has been updated by zverok (Victor Shepelev).


Ugh. I feel ashamed, honestly :)
Never thought about using `.slice` this way, somehow! It is definitely cleaner.
Can be closed.

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Feature #14444: MatchData: alias for #[]
https://bugs.ruby-lang.org/issues/14444#change-76206

* Author: zverok (Victor Shepelev)
* Status: Feedback
* Priority: Normal
* Assignee: 
* Target version: 
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After introduction of safe navigation operator and other latest features, it could be pretty idiomatic to do this:

```ruby
next_page = response.dig('meta', 'pagination', 'next')&.match(/&page=(\d+)/)&.[](1)
```

The ugly thing here is, obviously, `&.[](1)`. When dealing with other classes we can use `dig(one_key)` or `at(index)` for arrays, but for `MatchData` there are no good synonym/alias.

Two options come to mind:

* `&.capture(1)` — singular from "captures"
* `&.at(1)` — like it is in Array, from which MatchData already borrows `values_at`

Yes, several `&.` in a row could be said a code smell and example may feel a bit extreme.

But for simple matches, the principle stays the same: "match something and extract if matched" otherwise should be written in much less readable code like this:

```ruby
if url =~ /&page=(\d+)/
  next_page = Regexp.last_match[1]
end
# or
if (m = url.match(/&page=(\d+)/))
  next_page = m[1]
end

# this seems the most reasonable syntax anyways:
next_page = url.match(/&page=(\d+)/)&.at(1)
```



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