[ruby-core:115597] [Ruby master Feature#20027] Add Range Deconstruction

Issue #20027 has been updated by shan (Shannon Skipper).


Pattern matching would be another option though Range doesn't implement #deconstruct or #deconstruct_keys by default.

``` ruby
class Range def deconstruct = [self.begin, self.end] end

42..420 => low, high
```

Just an aside, but you could avoid the performance issues of splatting #to_a by using Range #begin and #end.

```ruby
low, high = (42..420).then { [_1.begin, _1.end] }
```

----------------------------------------
Feature #20027: Add Range Deconstruction
https://bugs.ruby-lang.org/issues/20027#change-105528

* Author: stuyam (Stuart Yamartino)
* Status: Open
* Priority: Normal
----------------------------------------
Ranges are a powerful tool in ruby. A common range I use is a date range such as `(Date.yesterday..Date.tomorrow)`. A range will often be passed around to methods because the dates hold meaning together such as a timeframe for a table filter.
Often I want to grab the original values out of a range like:
```ruby
timeframe = (Date.yesterday..Date.tomorrow)
start_date = timeframe.begin
end_date = timeframe.end

#=> start_date = yesterday
#=> end_date = today
```

Similar to array and hash deconstruction I thought it would be useful to support range deconstruction like this:
```ruby
start_date, end_date = (Date.yesterday..Date.tomorrow)

#=> start_date = yesterday
#=> end_date = today
```


This would also work for endless or beginless ranges since the beginning and end are just nil in those cases:
```ruby
start_date, end_day = ..Date.tomorrow

#=> start_date = nil
#=> end_date = tomorrow
```

You could do this now using `to_a` like:
```ruby
start_date, *middle_dates, end_date = (Date.new(2000,1,1)..Date.new(2023,1,1).to_a
```
However this has unnecessary performance issues by converting the range to an array especially if the range spans a large period, `middle_dates` would hold a very large array. Also if the range resulted in an array with 2 values, `end_date` would be nil and this wouldn't actually work to get the begin and end values.

I think this provides a simple interface for a common pattern of deconstructing ranges into their beginning and end values. It would be useful for ranges regardless of date ranges or other types of ranges since they are essentially tuples. Would love to know what others think about this <3



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