From: jean.boussier@... Date: 2019-10-21T13:09:22+00:00 Subject: [ruby-core:95455] [Ruby master Feature#16150] Add a way to request a frozen string from to_s Issue #16150 has been updated by byroot (Jean Boussier). Quick update on compatibility with this change. I opened PRs on the 5 affected gems I found: - https://github.com/googleapis/google-cloud-ruby/pull/4109 - https://github.com/matthewrudy/memoist/pull/82 - https://github.com/grpc/grpc/pull/20417 - https://github.com/pry/pry/pull/2084 - https://github.com/wvanbergen/activerecord-databasevalidations/pull/23 So far 2 have been merged and released, and 3 are awaiting a reaction from their respective maintainers. ---------------------------------------- Feature #16150: Add a way to request a frozen string from to_s https://bugs.ruby-lang.org/issues/16150#change-82207 * Author: headius (Charles Nutter) * Status: Closed * Priority: Normal * Assignee: Eregon (Benoit Daloze) * Target version: ---------------------------------------- Much of the time when a user calls to_s, they are just looking for a simple string representation to display or to interpolate into another string. In my brief exploration, the result of to_s is rarely mutated directly. It seems that we could save a lot of objects by providing a way to explicitly request a *frozen* string. For purposes of discussion I will call this to_frozen_string, which is a terrible name. This would reduce string allocations dramatically when applied to many common to_s calls: * Symbol#to_frozen_string could always return the same cached String representation. This method is *heavily* used by almost all Ruby code that intermingles Symbols and Strings. * nil, true, false, and any other singleton values in the system could similarly cache and return the same String object. * The strings coming from core types could also be in the fstring cache and deduplicated as a result. * User-provided to_s implementations could opt-in to caching and returning the same frozen String object when the author knows that the result will always be the same. A few ideas for what to call this: * `to_fstring` or `fstring` reflects internal the "fstring" cache but is perhaps not obvious for most users. * `to_s(frozen: true)` is clean but there will be many cases when the kwargs hash doesn't get eliminated, making matters worse. * `def to_s(frozen = false)` would be mostly free but may not be compatible with existing to_s params (like `Integer#to_s(radix)` This idea was inspired by @schneems's talk at RubyConf Thailand, where he showed significant overhead in ActiveRecord from Symbol#to_s allocation. -- https://bugs.ruby-lang.org/ Unsubscribe: