symbol-fstring is a Ruby extension that provide access to symbols internal string representations.
In Ruby many APIs tend to accept symbols, but regularly convert them to string internally. The typical example is
ActiveSupport::HashWithIndifferentAccess, but there are plenty more.
The problem with this is that
Symbol#to_s creates a new string every time it is invoked, and since it often happens
in hotspots, it causes a lot of work for the garbage collector, and cause many identical strings to be kept in memory.
There was an attempt to make
Symbol#to_s return its internal fstring for Ruby 2.7,
but unfortunately it got reverted, instead Ruby 3.0 should have
This gem backports the
Symbol#name method for older rubies, and optionally allow to replace
Add this line to your application's Gemfile:
And then execute:
Or install it yourself as:
$ gem install symbol-fstring
FString can be used in two ways.
By default this gem backport the Ruby 3.0
If your application and your dependencies are compatible with it, you can change
Symbol#to_s behavior globally with:
Or you can also add it this way in your Gemfile:
gem 'symbol-fstring', require: 'fstring/all'
Symbol#to_s (orig) 11.748M (± 1.7%) i/s - 58.786M in 5.005571s Symbol#name (patch) 18.067M (± 1.9%) i/s - 90.510M in 5.011549s
But there's also a reduced pressure on the garbage collector.
After checking out the repo, run
bin/setup to install dependencies. Then, run
rake test to run the tests. You can also run
bin/console for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run
bundle exec rake install. To release a new version, update the version number in
version.rb, and then run
bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the
.gem file to rubygems.org.
Bug reports and pull requests are welcome on GitHub at https://github.com/Shopify/symbol-fstring.
The gem is available as open source under the terms of the MIT License.