JamieMason

Group Array of JavaScript Objects by Key or Property Value

Implementation

const groupBy = key => array =>
  array.reduce((objectsByKeyValue, obj) => {
    const value = obj[key];
    objectsByKeyValue[value] = (objectsByKeyValue[value] || []).concat(obj);
    return objectsByKeyValue;

tim-field

import { useEffect, useState } from "react"
import { createBrowserHistory } from "history"
const history = createBrowserHistory()

const toLocation = path => new URL(path, window.location.href)

// without this react won't re-render as location is the same object
// @see https://reactjs.org/docs/hooks-reference.html#bailing-out-of-a-state-update
const cloneLocation = () => Object.assign({}, window.location)

tomhicks

/*
Copy this into the console of any web page that is interactive and doesn't
do hard reloads. You will hear your DOM changes as different pitches of
audio.

I have found this interesting for debugging, but also fun to hear web pages
render like UIs do in movies.
*/

const audioCtx = new (window.AudioContext || window.webkitAudioContext)()

erikig

nathanhleung

Fix macOS Hanging Issue

Problem

Hey Apple users:

If you're now experiencing hangs launching apps on the Mac, I figured out the problem using Little Snitch.

It's trustd connecting to http://ocsp.apple.com >

ctsrc

Guide: Run FreeBSD 13.1-RELEASE for ARM64 in QEMU on Apple Silicon Mac (MacBook Pro M1, etc) with HVF acceleration (Hypervisor.framework)

This guide was adapted from https://gist.github.com/niw/e4313b9c14e968764a52375da41b4278#running-ubuntu-server-for-arm64

Running FreeBSD 13.1-RELEASE for ARM64

1. Install Xcode from App Store or install Command Line Tools on your Mac running on Apple Silicon.

tangentstorm

// sh.mts: javascript shorthand

// #region array tools
/** id function (returns first argument) */
export const id=<T,>(x: T): T=>x
/** create an array filled with n copies of x */
export const af=<T,>(n: number, x: T): T[]=>Array(n).fill(x) // TODO: make this 'afl' or 'fil' (aa?)
/** loop i from 0..n, calling f(i) */
export const ii=(n: number, f: (i: number)=>void)=>{for(let i=0;i<n;i++)f(i)}
/** map f over [0..n]  */