The pattern of combining two elements is abstracte...

# arrow

[simon.vergauwen]

The pattern of combining two elements is abstracted with Semigroup.

interface Semigroup<A> {
  fun A.combine(b: A): A
  operator fun A.plus(b: A): A = this.combine(b)
}

You can then compose multiple Semigroup together.

import arrow.core.Option
import arrow.core.extensions.option.semigroup.semigroup
import arrow.core.extensions.semigroup

val example = Option.semigroup(Int.semigroup()).run {
  Option(1) + Option(2)
}