Two quick questions: 1) Where can I read about how...

# arrow

[Sagar Suri]

Two quick questions:
1) Where can I read about how Arrow optics compute over immutable data objects ?
2) what is the downside of using Reader monad for DI in comparison to framework like Dagger?

[simon.vergauwen]

Arrow-optics has its own website since recently! 🙂

[simon.vergauwen]

https://arrow-kt.io/docs/optics/dsl/

[simon.vergauwen]

I am hoping to revamp the docs soon, but that’s very time consuming 😞

If you have any questions, or are interessed in contributing to Optics I’d love to help you with anything 🙂

[simon.vergauwen]

This is a high level DSL build on top of Arrow Optics to work with Json. https://github.com/47deg/helios/tree/master/helios-optics

[Sagar Suri]

Thanks Simon! I wanna understand it’s internal working for now and will surely contribute once I get my head around this library. 😄

[aballano]

Related to Reader vs Dagger it's a tough comparison and would probably depend on the size of your project and personal taste

[rcd27]

Does Reader provide compile-time errors?

[aballano]

yes, because is based on types and properties

[aballano]

there's an article on that from our amazing @Jorge Castillo -> https://jorgecastillo.dev/kotlin-dependency-injection-with-the-reader-monad

[Jorge Castillo]

I wish there was a “bald guy using a laptop” emoji

[Sagar Suri]

That’s a great article! I am just looking how will scoping work with Reader?
How will this work with modularised apps?

[simon.vergauwen]

You’re just scoping val, fun and object. So it works based on visibility modifiers.

[simon.vergauwen]

No generated code around your dependencies just all plain library and user code

[Sagar Suri]

Yeah no generated code is a big win for us. Since doing a clean build takes ~36mins 💀 and dagger is the first in our list that is decrease the speed.

[pakoito]

https://www.pacoworks.com/2018/02/25/simple-dependency-injection-in-kotlin-part-1/

[pakoito]

check that as an alternative to DI frameworks

[pakoito]

https://arrow-kt.io/docs/patterns/dependency_injection/

[pakoito]

that’s the arrow-specific version