Sofia, Bulgaria Works at Toptal (https://toptal.com) Devoted to Emacs Author/maintainer of many Emacs and Clojure libraries and tools (e.g. Projectile, CIDER, nREPL, Orchard) Author of RuboCop, editor of the community Ruby Style Guide (https://rubystyle.guide), blah, blah, blah @bbatsov @bozhidarb on Reddit (long story) metaredux.com emacsredux.com
2020 The first major Ruby release since Ruby 2.0 (released way back in 2013) Official release notes (https://www.ruby-lang.org/en/news/2020/12/25/ruby-3-0-0-released/) Detailed release notes (https://rubyreferences.github.io/rubychanges/3.0.html)
lot in the past 10 years Rails is no longer hip Ruby is facing some fierce competition from newer languages like Clojure, Elixir, Go, Java, etc Ruby 3 has the ambitious goal to save Ruby’s future Matz has been talking about Ruby 3 since 2015 He had a keynote about Ruby 3 at EuRuKo 2016 in Sofia A lot of ideas for Ruby 3 have floated around since then
Ruby to node.js to Go, Rust, and Elixir. At first, each community is defined by its potential. But as that potential is realized, the community begins to be defined by its compromises. That change is felt most keenly by the people who were there first, who remember what it was like when anything seemed possible. They feel fenced in and so they move on, in search of their golden city.“ -- Zack Telman
The bundling of Bundler (Ruby 2.6) Gemifying the Standard Library (ongoing process) See https://stdgems.org/ for details Improvements to IRB syntax highlighting debugging capabilities Multi-line editing Performance improvements Improvements to RDoc
is a Hash, Ruby < 2.7 will automatically convert to keyword arguments. # Those are more or less the same in Ruby 2.x def foo(name, options = {}) end def bar(name, **options) End foo('Bruce Wayne', age: 10) bar('Bruce Wayne’, { age: 10 })
emits a warning, which is an error in Ruby 3. # Those are different in Ruby 3.x def foo(name, options = {}) end def bar(name, **options) End # Works, because you’re still passing a hash foo('Bruce Wayne', age: 10) # Doesn’t work anymore bar('Bruce Wayne’, { age: 10 }) # Magic fix bar('Bruce Wayne’, **{ age: 10 })
2.x def foo(name, options = {}) end def bar(name, **options) end # Let's pass a hash parameter foo('Bruce Wayne', {age: 10}) # Ruby 2.6: works # Ruby 2.7: warns: Using the last argument as keyword parameters is deprecated; maybe ** should be added to th e call # Ruby 3.0: ArgumentError (wrong number of arguments (given 2, expected 1)) bar('Bruce Wayne', age: 10) # => works h = {age: 10} bar('Bruce Wayne', **h) # => works, ** is mandatory # The last hash argument still allowed to be passed without {}: foo('Bruce Wayne', age: 10) # => works
including members of the core team felt “Matz is a boaster”. In fact, I felt so too. But we did. I am honored to see the core team actually accomplished to make Ruby 3.0 three times faster than Ruby 2.0 (in some benchmarks). – Matz
improvements in limited workloads, such as games (Optcarrot), AI (Rubykon), or whatever application that spends majority of time in calling a few methods many times. Although Ruby 3.0 significantly decreased a size of JIT-ed code, it is still not ready for optimizing workloads like Rails, which often spend time on so many methods and therefore suffer from i-cache misses exacerbated by JIT. Stay tuned for Ruby 3.1 for further improvements on this issue.
def square(x) = x * x # Not (so) good: has side effect def set_x(x) = (@x = x) def print_foo = puts("foo") # bad def fib(x) = if x < 2 x else fib(x - 1) + fib(x - 2) end
seeks the future with static type checking, without type declaration, using abstract interpretation. RBS & TypeProf are the first step to the future. More steps to come. — Matz
can be made by a User or a Bot def author: () -> (User | Bot) # Two overloads with/without blocks def each_reply: () -> Enumerator[Comment, void] | { (Comment) -> void } -> void ... end
Math.sqrt(number) end end # send parameters ractor1.send 3**71 ractor2.send 4**51 p ractor1.take #=> 8.665717809264115e+16 p ractor2.take #=> 2.251799813685248e+15
Assignment to numbered parameters (e.g. _1) will now result in a syntax error (it’s a warning in Ruby 2.7) yield in a singleton class definitions, which was deprecated in 2.7, will now result in a syntax error Another batch of IRB improvements Continued efforts to gemify the Ruby standard library (https://stdgems.org/)
RuboCop 1.7 The bulk of the work so far was related to endless method definitions The support for Ruby 3.0 will mature and evolve over the course of the next few months
bbatsov
rluisr
kuriko
wasabeef
mattdclarke
bassbone
texmeijin
hideg
shohata
ramsey
chirurimu
suzushin54
philnash
sferik
danielanewman
frogandcode
lara
phodgson
shpigford
lemiorhan
addyosmani
3n
hannesfritz
![arr = (1..10).to_a # Select first 6 elements arr[..5] #](https://files.speakerdeck.com/presentations/0646f20a92d34dd4a1f82691dc8a18d3/slide_59.jpg){kind=link}
![h = Hash.new { _1[_2] = "Go Fish: #{_2}" }](https://files.speakerdeck.com/presentations/0646f20a92d34dd4a1f82691dc8a18d3/slide_72.jpg){kind=link}
![PATTERN MATCHING # before def display_name(name_hash) if name_hash[:username] name_hash[:username] elsif](https://files.speakerdeck.com/presentations/0646f20a92d34dd4a1f82691dc8a18d3/slide_77.jpg){kind=link}
