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// List
type List<A> = Nil | Cons<A>;

interface Nil {
  readonly _tag: "Nil";
}

interface Cons<A> {
  readonly _tag: "Cons";
  readonly head: A;

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class Node {
    constructor(value) {
        this.value = value
        this.next = null
        this.prev = null
    }
}

class DoubleLinkedList {
    constructor(value) {

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class Node {
    constructor(value) {
        this.value = value
        this.next = null
    }
}

class LinkedList {
    constructor(value) {
        const newNode = new Node(value)

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const filterAsync = <T>(arr: T[], fn: (x: T) => Promise<boolean>) =>
  mapAsync(arr, fn).then((arr2) => arr.filter((_, i) => Boolean(arr2[i])));

(async () => {
  console.log("START FILTER");
  const filtered = await filterAsync([1, 2, 3, 4], async (n) => {
    const x = await fakeFilter(n);
    return x;
  });
  useResult(filtered);

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const forEachAsync = <T>(arr: T[], fn: (x: T) => any): Promise<any> =>
  arr.reduce(
    (promise: Promise<void>, value: T) => promise.then(() => fn(value)),
    Promise.resolve()
  );

(async () => {
  console.log("START FOREACH VIA REDUCE");
  await forEachAsync([1, 2, 3, 4], async (n) => {
    const x = await fakeAPI(n * 1000, n);

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const mapAsync = <T, R>(arr: T[], fn: (x: T) => Promise<R>) =>
  Promise.all(arr.map(fn));

(async () => {
  console.log("START MAP");
  const mapped = await mapAsync([1, 2, 3, 4], async (n) => {
    const x = await fakeAPI(n * 1000, n);
    return x * 10;
  });
  useResult(mapped);

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Install Helm

brew install helm

Initialize official Helm chart repository

helm repo add stable https://kubernetes-charts.storage.googleapis.com/

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Kubelet

• The kubelet is the agent that runs on each node, and is responsible for launching pods.
• It doesn't directly run containers but instead controls a runtime, such as Docker or rkt.
• The kubelet operates at the level of PodSpec, so it only knows how to launch pods.
• The kubelet also runs a tool called cadvisor that collects metrics about resource usage on the node, and using each container that is running on the node, this information can then be used by Kubernetes when making scheduling decisions.

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Install minikube

brew install minikube

Create minikube cluster

minikube start

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const { ApolloServer, gql, SchemaDirectiveVisitor } = require('apollo-server');
const { GraphQLScalarType, defaultFieldResolver, GraphQLString } = require('graphql');
const { Kind } = require('graphql/language');
const formatDate = require("dateformat");

const typeDefs = gql`
  directive @date(
    defaultFormat: String = "mmmm d, yyyy"
  ) on FIELD_DEFINITION