To be honest, I don't really understand Ruby either. It's like combination of performance of Python, compatibility of C, transparency of any mystery dependency + build system and yet another syntax on top of it.
For example: I mean, you can monkeypatch anything (including _Object_) at runtime. You can use this to make 1 + 1 = 3, if you desired, or to add a method to all instances of any class currently instantiated. Want your database to respond to .fuckoff(), no problem..
This kind of stuff is also how rspec (used to?) actually run tests.
It's cool, but also pretty insane.
irb(main):001:0> class Object
irb(main):002:1> def fuckoff
irb(main):003:2> "lol"
irb(main):004:2> end
irb(main):005:1> end
=> :fuckoff
irb(main):006:0> 5.fuckoff
=> "lol"
irb(main):007:0> "Hello World".fuckoff
=> "lol"
irb(main):008:0>The bad thing is that this is often abused horribly, I blame the Rails ecosystem with its "just add this gem to the Gemfile and it will magically change your application" attitude.
https://kotlinlang.org/docs/extensions.html
https://docs.scala-lang.org/scala3/book/ca-extension-methods...
In Ruby, however, there is no concept of an import. You can require other files but this is transitive. So if something anywhere in your chain of dependencies is defining a new method on String, or Object, it's available everywhere. Plus, in Rails usually you don't even have to require anything, as the framework magic does that for you.
The fact that there is no proper import/module system is easily one of my most disliked features about Ruby, it makes it incredibly hard to understand where things come from.
Also, Ruby doesn't only allow you to add new behaviour to existing classes. It also allows overriding existing methods. And that suffers from the exact same problems, i.e. it could be in some transitive dependency, and suddenly your strings will be doing things you didn't expect them to do...
F fuckoff(x) "lol"
echo(5.fuckoff())
echo("Hello World".fuckoff())But you get optional typing too for speed