From: "Dan0042 (Daniel DeLorme) via ruby-core" <ruby-core@...>
Date: 2023-12-22T17:03:32+00:00
Subject: [ruby-core:115866] [Ruby master Feature#20080] Implement #begin_and_end method on Range

Issue #20080 has been updated by Dan0042 (Daniel DeLorme).


Can you show an example use case that demonstrates the value of the feature?

Because
`first, last = (300..1).begin_and_end` is simpler as `first, last = 300, 1`
`first, last = r.begin_and_end` might as well be `first, last = r.first, r.last`
or just use `r.first` and `r.last` directly instead of local variables

----------------------------------------
Feature #20080: Implement #begin_and_end method on Range
https://bugs.ruby-lang.org/issues/20080#change-105823

* Author: stuyam (Stuart Yamartino)
* Status: Open
* Priority: Normal
----------------------------------------
Followup Reference: #20027 

This feature request is to implement a method called `#begin_and_end` on `Range` that returns an array of the first and last value stored in a range:
```ruby
(1..300).begin_and_end #=> [1, 300]

first, last = (300..1).begin_and_end
first #=> 300
last #=> 1
```
I believe this would be a great addition to Ranges as they are often used to pass around a single object used to hold endpoints, and this allows easier retrieval of those endpoints.
This would allow easier deconstruction into start and end values using array deconstruction as well as a simpler way to serialize to a more primitive object such as an array for database storage.
This implementation was suggested by @mame in my initial feature suggestion regarding range deconstruction: https://bugs.ruby-lang.org/issues/20027

This implementation would work similar to how `#minmax` works where it returns an array of two numbers, however the difference is that `#minmax` doesn't work with reverse ranges as @Dan0042 pointed out in the link above:
```ruby
(1..42).minmax #=> [1, 42]
(42..1).minmax #=> [nil, nil]
```





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