kotlin-coro-chain-of-responsibility.kt

package generator

import java.io.File

fun canHandle(func: () -> Boolean): Boolean {
    return func()
}

fun firstHandler(successor: Generator<String, String>? = null) = generate<String, String>{

    while (true) {
        val data = yield ("")
        if (canHandle { data.startsWith("2") }) {
           println("[ FirstHandler ] : Handling the line $data")
        }else {
            successor?.next(data)
        }
    }

}


fun secondHandler(successor: Generator<String, String>? = null) = generate<String, String>{
    while (true) {
        val data = yield ("")
        if (canHandle { data.startsWith("7") }) {
            println("[ SecondHandler ] : Handling the line $data")
        }else {
            successor?.next(data)
        }

    }
}

fun thirdHandler(successor: Generator<String, String>? = null) = generate<String, String> {
    while (true) {
        val data = yield ("")
        if (canHandle { data.startsWith("8") }) {
            println("[ ThirdHandler ] : Handling the line $data")
        }else {
            successor?.next(data)
        }

    }
}


fun startHandlers(lst: List<Generator<String, String>>){
    for (item in lst){
        item.next("")
    }
}

fun main(args: Array<String>) {
    val first = firstHandler()
    val second = secondHandler(first)
    val third = thirdHandler(second)

    startHandlers(listOf(first, second, third))

    val file = File("/Users/smitaldesai/IdeaProjects/kotlintrials/src/main/kotlin/iter/access-log")
    for (line in file.bufferedReader().lineSequence()) {
        third.next(line)
    }

}