Ryohji Ikebe ryohji

P.211 ～ 212 の部分再帰関数の実装。名前づけで混乱したので整理しなおしてみた。

# 部品１
def zero
    0
end

# 部品２
def increment(n)
 n + 1

val mutex = java.util.concurrent.locks.ReentrantLock()

const val FULL = 2
var que = 0

fun prod() {
    while (true) {
        // P0: lock
 mutex.lock()

ListView

ListView は、その表示するリスト項目の内容を保持する（そしてその内容を表示するためのビューを返す） ListAdapter をつなぐことで動作する。

class Adapter : BaseAdapter() {

    override fun getView(position: Int, convertView: View?, parent: ViewGroup): View =

	import android.graphics.ImageFormat.NV21
	import android.graphics.Rect
	import android.graphics.YuvImage
	import android.media.Image
	import java.io.ByteArrayOutputStream

	object Converter {

	fun jpegByteArrayFrom(yuv420_888: Image): ByteArray =
	yuv420_888.nv21ByteArray

	fun <E> Collection<Collection<E>>.directProduct(): List<List<E>> =
	if (isEmpty()) {
	listOf()
	} else {
	val (head, rest) = first() to drop(1)
	head.map(::listOf).let {
	if (rest.isEmpty()) {
	it
	} else {
	rest.directProduct().flatMap { tail -> it.map { h -> h + tail } }

	interface State

	interface Event

	data class Transition(val event: Event, val state State)

	val transitions: Map<State, Set<Transition>) = ...

	package app

	fun main() {
	val rules: List<Rule> = listOf(
	object : Rule {
	override val name = "read"
	override fun applicable(shared: Shared, thread: Thread) = thread.ir == Location.P0
	override fun convert(shared: Shared, thread: Thread) = shared to Local(Location.P1, shared.x)
	},
	object : Rule {

	object Executor {
	val uiExecutor = Handler(Looper.getMainLooper()).toExecutor()
	val ioExecutor = LooperThread().also { it.start() }.getHandler().toExecutor()

	private fun Handler.toExecutor(): Executor = Executor {
	while (!post(it)) {
	Thread.sleep(0)
	}
	}

	const Z = f => (x => f(y => x(x)(y)))(x => f(y => x(x)(y)));
	const fact = Z(f => x => x != 0 ? x * f(x-1) : 1);
	fact(5); // => 120

	#include <cstdio>

	int main() {
	auto z = [](auto f) {
	auto g = [&f](auto x) {
	return f([&x](auto y) { return x(x)(y); });
	};
	return g(g);
	};
	auto f = [](auto f) {