From: shevegen@...
Date: 2019-05-07T16:47:35+00:00
Subject: [ruby-core:92590] [Ruby trunk Feature#15836] [Proposal] Make Module#name and Symbol#to_s return their internal fstrings

Issue #15836 has been updated by shevegen (Robert A. Heiler).


> frozen_string_literalAFAIK should become the default some day

Matz said that but it will not be for ruby 3.0 at the least.

In my own code bases I am using frozen strings a lot, through the shebang; either
"# frozen_string_literal: false" (initially) but these days more and more
"# frozen_string_literal: true". I think other ruby users may be able to transition
into frozen strings if enough time is given AND recommendations are given from the
ruby core team in due time whenever there are (future) changes.

> string used as hash keys are now automatically interned as well.

Although the use case for HashWithIndifferentAccess (I hate how long that name
is ...) is probably not completely void, with strings being frozen it appears to
me as if one use case (the speed factor) is nullified. There may be still other
use cases probably, such as API design e. g. when people have to make a decision
between "do I have to use a String or a Symbol here". Personally I like both
strings and symbols, though; I think jeremy evans once gave a good explanation
or wrote documentation to emphasis the distinction in the official doc (but I
may misremember).

----------------------------------------
Feature #15836: [Proposal] Make Module#name and Symbol#to_s return their internal fstrings
https://bugs.ruby-lang.org/issues/15836#change-77951

* Author: byroot (Jean Boussier)
* Status: Feedback
* Priority: Normal
* Assignee: 
* Target version: 
----------------------------------------
# Why ?

In many codebases, especially Rails apps, these two methods are the source of quite a lot of object allocations.

`Module#name` is often accessed for various introspection features, autoloading etc.

`Symbol#to_s` is access a lot by HashWithIndifferentAccess other various APIs accepting both symbols and strings. 

Returning fstrings for both of these methods could significantly reduce allocations, as well as sligthly reduce retention as it would reduce some duplications.

Also, more and more Ruby APIs are now returning fstrings. `frozen_string_literal`AFAIK should become the default some day, string used as hash keys are now automatically interned as well.

### Backward compatibilty 

Of course this is not fully backward compatible, it's inevitable that some code in the wild is mutating the strings returned by these methods, but I do believe it's a rare occurence, and easy to fix. 

### Implementation

I implemented it here: https://github.com/ruby/ruby/pull/2175



-- 
https://bugs.ruby-lang.org/

Unsubscribe: <mailto:ruby-core-request@ruby-lang.org?subject=unsubscribe>
<http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>