From: marcandre-ruby-core@... Date: 2020-12-18T06:44:14+00:00 Subject: [ruby-core:101509] [Ruby master Feature#16274] Transform hash keys by a hash Issue #16274 has been updated by marcandre (Marc-Andre Lafortune). solnic (Piotr Solnica) wrote in #note-18: > marcandre (Marc-Andre Lafortune) wrote in #note-17: > > Closing, since this has been committed by Nobu ���� (in b25e27277dc39) > > > > I just added doc (in 8558d5e48) > > This is a wonderful addition but is there a chance you'd reconsider it? Instead of making `transform_keys` more complex, wouldn't it be better to introduce `Hash#rename_keys` instead? It could be even built on top of `Hash#transform_keys`. It looks like you are replying to me, but of course this is Matz' decision. That said I feel that the current name is good, especially since you can mix and match hash-mapping and block. ---------------------------------------- Feature #16274: Transform hash keys by a hash https://bugs.ruby-lang.org/issues/16274#change-89291 * Author: sawa (Tsuyoshi Sawada) * Status: Closed * Priority: Normal * Target version: 3.0 ---------------------------------------- We have `Hash#transform_keys` and its bang version to change the keys of a hash, but that requires passing a block, which assumes that the mapping from the old keys to the new keys follows some rule. But in reality, we frequently want to change the keys where it is difficult to provide a rule. For example, suppose we have: ``` hash = {created: 2019-10-23 17:54:46 +0900, updated: 2019-10-23 17:59:18 +0900, author: "foo"} ``` and want to achieve: ``` {created_at: 2019-10-23 17:54:46 +0900, update_time: 2019-10-23 17:59:18 +0900, author: "foo"} ``` I request an option to change the keys of a hash not by giving a block, but by passing a hash. I came up with two options. ### 1. Argument for `Hash#transform_keys` and its bang version Allow `Hash#transform_keys` to optionally take a hash argument instead of a block. ``` hash.transform_keys({created: :created_at, updated: :update_time}) # => {created_at: 2019-10-23 17:54:46 +0900, update_time: 2019-10-23 17:59:18 +0900, author: "foo"} ``` ### 2. Argument for `Hash#slice` and the counterparts in other classes Since `Hash#slice` is often the first step of modifying a hash into some other hash form, it makes sense to let it take an optional hash argument. ``` hash.slice(:created, :author, transform_keys: {created: :created_at}) # => {created_at: 2019-10-23 17:54:46 +0900, author: "foo"} ``` With option 1, it could make sense to even allow a hash argument and a block simultaneously: ``` hash.transform_keys({created: :created_at, updated: :update_time}, &:to_s) # => {"created_at" => 2019-10-23 17:54:46 +0900, "update_time" => 2019-10-23 17:59:18 +0900, "author" => "foo"} ``` -- https://bugs.ruby-lang.org/ Unsubscribe: