Issue #19001 has been updated by RubyBugs (A Nonymous). Agreed, this need ended up being met by the initial implementation! Thank you, closing this ticket. zverok (Victor Shepelev) wrote in #note-2:
There isn't any need for this ticket as a separate request, as far as I am concerned. It works in the initial implementation of data already as submitted in https://bugs.ruby-lang.org/issues/16122#note-68, and even works with ol' good Struct, too: ```ruby Point = Struct.new(:x, :y, :z)
Point[1, 0, 0].to_h.then { Point[**_1] } == Point[1, 0, 0] # => true ```
---------------------------------------- Feature #19001: Data: Add #to_h symmetric to constructor with keyword args [Follow-on to #16122 Data: simple immutable value object] https://bugs.ruby-lang.org/issues/19001#change-108768 * Author: RubyBugs (A Nonymous) * Status: Open ---------------------------------------- *Extracted a follow-up to [#16122 Data: simple immutable value object](https://bugs.ruby-lang.org/issues/16122)* # Proposal: Add a `#to_h` method symmetric to a constructor accepting keyword arguments This allows round-trip between a `Hash` and a Value object instance, for example: ```ruby Point = Data.define(:x, :y, :z) points = [ Point.new(x: 1, y: 0, z: 0), Point.new(x: 0, y: 1, z: 0), Point.new(x: 0, y: 0, z: 1), ] hashes = points.map(&:to_h) points_2 = hashes.map { |h| Point.new(**h) } points_2 == points #=> true ``` ## Why? Having symmetric operation between `#to_h` and a keyword-args constructor is a major ergonomic factor in usage of immutable value objects. To play with code that works like this, you may take a look at the [Values gem](https://rubygems.org/gems/values) ## Alternatives If there is no symmetric construction and de-construction along these lines, a number of use cases become more complicated and less ergonomic. -- https://bugs.ruby-lang.org/