About Promises

Kyle Simpson's Comment

https://www.linkedin.com/feed/update/urn:li:activity:6925833220617818112?commentUrn=urn%3Ali%3Acomment%3A(activity%3A6925833220617818112%2C6925852064862408704)

OP

https://www.linkedin.com/posts/aamir-muhammad-amin-a80a0421a_javascript-activity-6925833220617818112-wLKg?utm_source=linkedin_share&utm_medium=member_desktop_web

Currying and function composition in programming/JavaScript

Curry and Function Composition. Note: This is part of the “Composing… | by Eric Elliott | JavaScript Scene | Medium

When I was helping my cousin's son with his algebra homework, one of the questions was about creating a composite function in math. When I looked it up it reminded me so much of currying.

I asked on Twitter if I was the only one who saw the connection and I wasn't:

https://xstate.js.org/docs/

Iterables

Some things to think about when comparing languages and how learning one can help you better understand another, in this case, how iterators in Python have helped me understand how to use iterables in JavaScript

Async/Await

const fetch = require("node-fetch");

async function showGitHubUser(handle) {
    const url = `[](https://api.github.com/users/)[https://api.github.com/users/](https://api.github.com/users/)[](https://api.github.com/users/)${handle}`;
    const response = await fetch(url);
    const user = await response.json();
    console.log(user.name);
    console.log(user.location);
}

showGitHubUser("mariusschulz");

const fetch = require("node-fetch");

async function showGitHubUser(handle) {
    const url = `https://api.github.com/users/${handle}`;
    const response = await fetch(url);
    return await response.json();
}

showGitHubUser("mariusschulz")
    .then(user => {
        console.log(user.name);
        console.log(user.location);
    });

const fetch = require("node-fetch");

class GitHubApiClient {
    async fetchUser(handle) {
        const url = `https://api.github.com/users/${handle}`;
        const response = await fetch(url);
        return await response.json();
    }
}

(async () => {
    const client = new GitHubApiClient();
    const user = await client.fetchUser("mariusschulz");
    console.log(user.name);
    console.log(user.location);
})();

const fetch = require("node-fetch");

async function fetchFromGitHub(endpoint) {
    const url = `https://api.github.com${endpoint}`;
    const response = await fetch(url);
    const json = await response.json();

    if (response.status !== 200)
        throw Error(json.message);

    return json;
}

async function showGitHubUser(handle) {
    try {
        const user = await fetchFromGitHub(`/users/${handle}`);
        console.log(user.name);
        console.log(user.location);
    } catch (error) {
        console.error(`Error: ${error.message}`);
    }
}

showGitHubUser("mariusschulz");

const fetch = require("node-fetch");

async function fetchFromGitHub(endpoint) {
    const url = `https://api.github.com${endpoint}`;
    const response = await fetch(url);
    return await response.json();
}

async function showUserAndRepos(handle) {
    const userPromise = fetchFromGitHub(`/users/${handle}`);
    const reposPromise = fetchFromGitHub(`/users/${handle}/repos`);

    const user = await userPromise;
    const repos = await reposPromise;

    console.log(user.name);
    console.log(`${repos.length} repos`);
}

showUserAndRepos("mariusschulz");

const fetch = require("node-fetch");

async function fetchFromGitHub(endpoint) {
    const url = `https://api.github.com${endpoint}`;
    const response = await fetch(url);
    return await response.json();
}

async function fetchUserAndRepos(handle) {
    const [user, repos] = await Promise.all([
        fetchFromGitHub(`/users/${handle}`),
        fetchFromGitHub(`/users/${handle}/repos`)
    ]);

    console.log(user.name);
    console.log(`${repos.length} repos`);
}

fetchUserAndRepos("mariusschulz");

const Bluebird = require("bluebird");

async function main() {
    console.log("Working ...");
    await Bluebird.delay(2000);
    console.log("Done.");
}

main();

Symbol.asyncIterator = Symbol.asyncIterator || Symbol("asyncIterator");

const delay = (ms) => new Promise(resolve => {
    setTimeout(resolve, ms);
});

async function* someGenerator() {
    await delay(1000);
    yield 1;
    await delay(1000);
    yield 2;
    await delay(1000);
    yield 3;
}

async function main() {
    for await (const value of someGenerator()) {
        console.log(value);
    }
}

main();