From: "matheusrich (Matheus Richard) via ruby-core" <ruby-core@...>
Date: 2024-03-12T17:38:32+00:00
Subject: [ruby-core:117120] [Ruby master Feature#20298] Introduce `Time()` type-cast / constructor.

Issue #20298 has been updated by matheusrich (Matheus Richard).


To give some outside perspective, Rust often uses `from` to convert from a type to another. This could be one option for us

```rb
Time.from(whatever)
```

----------------------------------------
Feature #20298: Introduce `Time()` type-cast / constructor.
https://bugs.ruby-lang.org/issues/20298#change-107196

* Author: ioquatix (Samuel Williams)
* Status: Open
----------------------------------------
Many Ruby primitive types have constructors, e.g. `Integer(...)`, `String(...)`, `Float(...)`, etc. These usually convert from some subset of types, e.g. `Float(1) -> 1.0` will convert an Integer to a Float, and `Float("1") -> 1.0` will parse a String to a Float, and similar for other type casts/constructors.

I'd like to propose we introduce something similar for `Time` (and possibly this extends to `Date`/`DateTime` in a follow up proposal).

Suggested implementation could look something like this:

```ruby
def Time(value)
  case value
  when Time
    value
  when Integer
    Time.at(value)
  when String # The format is assumed to be the result of `Time#to_s`.
    Time.new(value)
  else
    value.to_time
  end
end
```

Alternatively, we might like to be a little more specific with the `else` clause/error handling.

## Background

In a project, I need to support multiple serialization formats/coders, including MessagePack, Marshal and JSON.

While Marshal and MessagePack are capable of serializing `Time` instances, `JSON` is not.

The code looks a bit like this:

```
data = fetch_job_data
job = @coder.load(data)
scheduled_at = Time(job[:scheduled_at]) # Hypothetical type-cast as outlined above
```

## Additional Observations

While some primitive data types accept themselves as arguments and construct by copy, e.g. `Array.new(Array.new)`, others do not, e.g. `Hash` and `Time`. Perhaps `Time.new(Time.new)` should behave similarly to `Array.new(Array.new)` - the outer instance is a copy of the inner.




-- 
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