Dysfunctional Ruby

A short 30min talk for Malaga Scala Meetup about caticorns and why rubyists deserve better.

http://www.meetup.com/es/Malaga-Scala/events/223598765

Transcript

1. Dysfunctional Ruby Málaga Scala Meetup, July 2015 Nando Sola
2. 1. The trouble with nil 2. The inheritance crisis 3. Bad romance overflow 4. Please don’t mutate my feelings 5. Share the love, not the state 6. True love scales
3. 1. The trouble with nil nil is a leaked abstraction Don’t take nil for granted
4. Procedural code gets information then makes decisions. Object-oriented code tells objects to do things. — Alec Sharp, “Smalltak by Example” http://sdmeta.gforge.inria.fr/FreeBooks/ByExample/SmalltalkByExampleNewRelease.pdf https://pragprog.com/articles/tell-dont-ask
5. https://github.com/pzol/deterministic http://egonschiele.github.io/contracts.ruby/ My weird Ruby
6. 2. The inheritance crisis Extending core classes in Ruby is a bad idea Integers are “immediates”, ie. architecture-dependent The rest are implemented in C (MRI/YARV), for efficiency http://words.steveklabnik.com/beware-subclassing-ruby-core-classes
7. Inheritance homogeneity FTL? In Ruby, inheritance is not encouraged http://ducktypo.blogspot.com.es/2010/08/why-inheritance-sucks.html Ruby’s “red pills”
8. 3. Bad romance overflow These implementations will fail for large values of n SystemStackError: stack level too deep why?
9. Ruby (YARV) has TCO since version 1.9 JRuby depends on the JVM optimizations Rubinius won’t implement TCO http://chris.mowforth.com/posts/2011/avoiding-stack-overflow-in-ruby-with-trampolines/ http://blog.vmoroz.com/posts/2015-04-18-generic-recursion-in-ruby-with-trampolines-and-thunks.html Solution: be agnostic (and lazy)
10. 4. Please don’t mutate my feelings In Ruby, only Fixnum and Symbol are immutable Using Struct and OpenStruct is not OK #freeze and #dup are not your friends
11. http://ruby-doc.org/core-2.0.0/Enumerator/Lazy.html https://github.com/hamstergem/hamster https://github.com/tcrayford/Values Use the std and core libraries Use gems that provide immutability Namespace pollution Expect a good deal of metaprogramming under the hood Compatibility with the other “good gems”
12. 5. Share the love, not the state Ruby (YARV) just provides Thread and Fiber primitives Their underlying implementations vary from GIL to 1:1 models Rubinius and JRuby: real multithreading Rubinius provides an additional actor model http://merbist.com/2011/02/22/concurrency-in-ruby-explained/ http://www.jstorimer.com/products/working-with-ruby-threads http://rubini.us/doc/en/systems/concurrency/
13. Use an implementation-agnostic gem for concurrency Advanced thread sync mechanisms Futures/Promises Channels Actors I/O reactor If possible, use Rubinius or JRuby Real threads Look for servers/clients using these https://github.com/celluloid/celluloid https://github.com/ruby-concurrency/concurrent-ruby https://github.com/celluloid/celluloid-io
14. https://twitter.com/yukihiro_matz/status/495219763883163648
15. 6. True love scales Ruby has a remote object framework in its stdlib (dRuby) Enables remote method calling Peer to peer Each remote method invocation is handled synchronously by a new server thread Not truly concurrent (Mutex needed) A distributed, immutable “tuplespace" is shared among all objects (Rinda) https://news.ycombinator.com/item?id=4696027 http://ruby-doc.org/docs/Distributed%20Ruby%20(drb%20and%20Rinda)/DistributedRuby.pdf
16. JRuby Mikka Java-flavored Akka Rubinius rubinius-actor Remoting is “bleeding-edge” Agnostic: DCell (distributed objects for Ruby) External systems: Redis, RabbitMQ, … https://github.com/iconara/mikka https://www.ruby-forum.com/topic/5957087 http://doc.akka.io/docs/akka/snapshot/java/untyped-actors.html
18. Use a functional language Scala, Clojure and Erlang have (most of) all of these features already baked-in No need for extra gems No need to stretch the boundaries of the language No need to hide anymore
19. Thanks! @mr_solo github.com/nandosola http://www.planetminecraft.com/skin/ruby--steven-universe/ All images are memes or can be found CC’d in Flicker. Cover art by