RB (Archive) rbrcsk

Why using the `children` prop makes `React.memo()` not work

I've recently ran into a pitfall of [React.memo()][memo] that seems generally overlooked; skimming over the top results in Google just finds it mentioned in passing in a [React issue][regit], but not in the [FAQ] or API [overview][react-api], and not in the articles that set out to explain React.memo() (at least the ones I looked at). The issue is specifically that nesting children defeats memoization, unless the children are just plain text. To give a simplified code example:

const Memoized = React.memo(({ children }) => (<div>{children}</div>));
// Won't ever re-render
<Memoized>bar</Memoized>
// Will re-render every time; the memoization does nothing

I use tmux splits (panes). Inside one of these panes there's a Vim process, and it has its own splits (windows).

In Vim I have key bindings C-h/j/k/l set to switch windows in the given direction. (Vim default mappings for windows switching are the same, but prefixed with C-W.) I'd like to use the same keystrokes for switching tmux panes.

An extra goal that I've solved with a dirty hack is to toggle between last active panes with C-\.

Here's how it should work:

	###
	### [2023-06-19] UPDATE: Just tried to use my instructions again on a fresh install and it failed in a number of places.
	###. Not sure if I'll update this gist (though I realise it seems to still have some traffic), but here's a list of
	###. things to watch out for:
	### - Check out the `nix-darwin` instructions, as they have changed.
	### - There's a home manager gotcha https://github.com/nix-community/home-manager/issues/4026
	###

	# I found some good resources but they seem to do a bit too much (maybe from a time when there were more bugs).
	# So here's a minimal Gist which worked for me as an install on a new M1 Pro.

	// Use your MDX content with this component.

	import React from 'react'
	import MDX from '@mdx-js/runtime'
	import components from '../utils/markdown/markdown'

	// Renders a cimple loading spinner as a test
	import Loading from './Loading'

	const mdxComponents = {

	# shows all url+titles of Chrome along with front window+tab url+title
	set titleString to ""

	tell application "Google Chrome"
	set window_list to every window # get the windows

	repeat with the_window in window_list # for every window
	set tab_list to every tab in the_window # get the tabs

	repeat with the_tab in tab_list # for every tab

	# Hello, and welcome to makefile basics.
	#
	# You will learn why `make` is so great, and why, despite its "weird" syntax,
	# it is actually a highly expressive, efficient, and powerful way to build
	# programs.
	#
	# Once you're done here, go to
	# http://www.gnu.org/software/make/manual/make.html
	# to learn SOOOO much more.

	#!/usr/bin/env python
	# saved to ~/bin/batcharge.py and from
	# http://stevelosh.com/blog/2010/02/my-extravagant-zsh-prompt/#my-right-prompt-battery-capacity
	#!/usr/bin/env python
	# coding=UTF-8

	import math, subprocess

	p = subprocess.Popen(["ioreg", "-rc", "AppleSmartBattery"], stdout=subprocess.PIPE)
	output = p.communicate()[0]

	{
	"imports": {
	"lodash": "./node_modules/lodash-es/lodash.js"
	}
	}

	#!/usr/bin/env python

	# based on cb-exit used in CrunchBang Linux <http://crunchbanglinux.org/>

	import pygtk
	pygtk.require('2.0')
	import gtk
	import os
	import getpass

-/**
- * Using Google Apps Script to enhance my gmail filters.
- *
- * I constantly receive email that are important for a short period of time (When I order food online!!!!) but after
- * the email is no longer relative (When I get my food!) I have no need for this email. Sadly they tend to pile up on me
- * (I eat a lot).
- *
- * Anyways you can add this 8hrDelete.gs file to https://script.google.com and set it up on a "Time Driven" trigger at what
- * ever time you'll like. I run it at midnight
- */

RB (Archive) rbrcsk

Why using the children prop makes React.memo() not work

Why using the `children` prop makes `React.memo()` not work