Feature #20298
Updated by ioquatix (Samuel Williams) 9 months ago
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) Time.parse(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.