James Newton jameswritescode

The Freenode resignation FAQ, or: "what the fuck is going on?"

IMPORTANT NOTE:

It's come to my attention that some people have been spamming issue trackers with a link to this gist. While it's a good idea to inform people of the situation in principle, please do not do this. By all means spread the word in the communities that you are a part of, after verifying that they are not aware yet, but unsolicited spam is not helpful. It will just frustrate people.

Update 3 (May 24, 2021)

A number of things have happened since the last update.

Advanced memoization and effects in React

Memoization is a somewhat fraught topic in the React world, meaning that it's easy to go wrong with it, for example, by [making memo() do nothing][memo-pitfall] by passing in children to a component. The general advice is to avoid memoization until the profiler tells you to optimize, but not all use cases are general, and even in the general use case you can find tricky nuances.

Discussing this topic requires some groundwork about the technical terms, and I'm placing these in once place so that it's easy to skim and skip over:

Memoization means caching the output based on the input; in the case of functions, it means caching the return value based on the arguments.
Values and references are unfortunately overloaded terms that can refer to the low-level implementation details of assignments in a language like C++, for example, or to memory

ANSI Escape Sequences

Standard escape codes are prefixed with Escape:

Ctrl-Key: ^[
Octal: \033
Unicode: \u001b
Hexadecimal: \x1B
Decimal: 27

Receive GOES-16 and GOES-17 Images with a Raspberry Pi and RTL-SDR dongle

Also see the original Pieter Noordhuis's guide

Hardware

You need:

Raspberry Pi Model B (or B+) with a MicroSD Card $35-40
An RTL-SDR dongle:

This document has moved!

It's now here, in The Programmer's Compendium. The content is the same as before, but being part of the compendium means that it's actively maintained.

Foldl vs Foldr

I like to call foldr as "fold from the right", while foldl is "fold from the left".

	# frozen_string_literal: true

	require 'delegate'

	class Fiberator < DelegateClass Fiber
	class Rewind < StandardError
	end
	NOTHING = Object.new
	private_constant :NOTHING

	# to run:
	# > elixir --no-halt udp_server.exs
	# to test:
	# > echo "hello world" \| nc -u -w0 localhost 2052
	# > echo "quit" \| nc -u -w0 localhost 2052

	# Let's call our module "UDPServer"
	defmodule UDPServer do
	# Our module is going to use the DSL (Domain Specific Language) for Gen(eric) Servers
	use GenServer

	let g:airline#themes#seoul256#palette = {}

	function! airline#themes#seoul256#refresh()

	let M0 = airline#themes#get_highlight('Special')
	let accents_group = airline#themes#get_highlight('Special')
	let modified_group = [M0[0], '', M0[2], '', '']
	let warning_group = airline#themes#get_highlight2(['airline_warning', 'bg'], ['airline_warning', 'fg'])

	let s:N1 = airline#themes#get_highlight2(['Normal', 'bg'], ['StatusLine', 'fg'])

	ctrl_table = {
	sends_escape = true,
	last_mods = {}
	}

	control_key_timer = hs.timer.delayed.new(0.15, function()
	ctrl_table["send_escape"] = false
	-- log.i("timer fired")
	-- control_key_timer:stop()
	end