I feel like if spring was written using kotlin originally, it would just use objects a lot instead o...

# spring

[Hullaballoonatic]

I feel like if spring was written using kotlin originally, it would just use objects a lot instead of injection, but that's because i'm under the impression that beans are just singletons

[Shawn A]

Injection is fine and kotlin allows you to do it declaratively without a proxies, annotations processors or byte code manipulation.

[fred.deschenes]

Plus you can let users modify/extend the injected stuff, whereas objects are final

[xenoterracide]

objects aren’t final by default… actually making them final by default (which kotlin does) is a violation of SOLID (the O for open/closed (open for extension, closed for modificaton) and extension methods violate the closed for modification.

[xenoterracide]

also you can do injection just fine in spring without proxies, or byte code manipulation, or annotation processors

[xenoterracide]

sure you need some of that for super advanced features… but you would need them in kotlin too

[xenoterracide]

like transaction handling

[xenoterracide]

there’s no way to add that code around your code without doing one of the above

[Shawn A]

Most of the AOP features in spring are doing that sort of thing. You can use other approaches like delegation or wrapping code in lambdas and kotlin supports that nicely.

[xenoterracide]

proxies are basically delegation/wrapping 😉

[Shawn A]

agree with you there.

[Quy D X Nguyen]

Extension methods violate SOLID no more than static methods or functions as some languages call them.

[xenoterracide]

eh, that’s a bit like arguing that since it’s all machine code in the end… imho, or whether or not myMethod( foo: Foo ) and myMethod( bar: Bar) represents a form of polymorphism (the latter is considered polymorphic), I would use the latter to argue that since in the language it “looks” like you’re calling the same method, that if in kotlin it looks like you’re calling a method on object, but that method doesn’t really exist on object, then you’ve essentially modified the object and/or changed its behavior, it doesn’t matter that it doesn’t compile to that. but that’s, like, just my opinion, man

[Quy D X Nguyen]

I mean extension methods don't give you anything normal methods don't. You may be mistaking these for c++ friend functions which can access internals.