Kondenko

@ExperimentalCoroutinesApi
fun <T> Flow<T>.bufferList(capacity: Int): Flow<List<T>> {
    require(capacity > 0) { "Buffer size should be positive, but was $capacity" }
    var buffer = listOf<T>()
    return transform { value ->
        if (buffer.size == capacity) emit(buffer)
        else buffer = buffer + value
    }
}

Kondenko

class DiffUtilDelegate<T, VH : RecyclerView.ViewHolder, A : RecyclerView.Adapter<VH>>(
        initialValue: List<T>,
        private val callbackFactory: (List<T>, List<T>) -> DiffUtil.Callback =
                { old, new -> SimpleCallback(old, new) }
) {

    private var currentValue: List<T> = initialValue

    operator fun setValue(thisRef: A?, property: KProperty<*>, value: List<T>) {
        val callback = callbackFactory(currentValue, value)

Kondenko

package com.kondenko.pocketwaka.utils

import io.reactivex.Observable
import io.reactivex.ObservableOperator
import io.reactivex.Observer
import io.reactivex.disposables.Disposable

fun <T, R> Observable<T>.scanMap(initialValue: T? = null, scanMap: (T, T) -> R): Observable<R> =
      lift(ScanMap(initialValue, scanMap))