0xameer

HASKELL PROGRAMMING FROM FIRST PRINCIPLES

CHAPTER1. ALL YOU NEED IS LAMBDA

1.1 All You Need is Lambda

lambda calculus:

computation model, 1930s, Alonzo Church, formalizing a method, Turing machines

Ok, I geeked out, and this is probably more information than you need. But it completely answers the question. Sorry. ☺

Locally, I'm at this commit:

$ git show
commit d6cd1e2bd19e03a81132a23b2025920577f84e37
Author: jnthn <[email protected]>
Date:   Sun Apr 15 16:35:03 2012 +0200

When I added FIRST/NEXT/LAST, it was idiomatic but not quite so fast. This makes it faster. Another little bit of masak++'s program.

I was trying to configure native ipv6 on my NixOS box, which is running in online.net's datacenters. They provide you a /48 or smaller subnet and a DUID which is used during DHCP. In dhcpcd vocabulary DUID is called clientid.

online.net's help page about IPv6 configuration was not very useful, since NixOS uses dhcpcd by default. The page which allowed me to make it all work was https://community.online.net/t/tutorial-ipv6-with-dhcpcd/3804

It looks like the only really required entries in networking.dhcpcd.extraConfig are interface and static though. I assumed that clientid is also necessary, but it looks like dhcpcd cares much more about content of /etc/dhcpcd.duid. Of course replace enp2s0 with the name of the main interface.

	test.html: test.md tufte-css.lua html5.html
	pandoc -t tufte-css.lua -f markdown -c tufte.css --template html5.html test.md > test.html

	html5.html:
	pandoc -D html5 > html5.html

	# -- mode: ruby --
	# vi: set ft=ruby :

	# All Vagrant configuration is done below. The "2" in Vagrant.configure
	# configures the configuration version (we support older styles for
	# backwards compatibility). Please don't change it unless you know what
	# you're doing.
	Vagrant.configure(2) do \|config\|
	# The most common configuration options are documented and commented below.
	# For a complete reference, please see the online documentation at

	{-# LANGUAGE DeriveFunctor #-}
	{-# LANGUAGE LambdaCase #-}

	import Control.Applicative (liftA2)
	import Data.Char
	import Data.Foldable (for_)
	import Data.Functor
	import qualified Data.HashMap.Strict as M
	import Data.List (intercalate)
	import Prelude hiding (any)

	Rough procedure for updating cargo hashes. Warning: this still requires a lot
	of manual work to cover all bases. Based on:

	https://github.com/NixOS/nixpkgs/pull/112764/commits/2650d5d2b8c19844224f8b368887153e2f18fdae

	# Invalidate all hashes

	rg -l "cargoHash" \| grep "\.nix" \| xargs -n1 sed -i -re 's/cargoHash = "..../cargoHash = "sha256-1234/g'
	rg -l "cargoSha256" \| grep "\.nix" \| xargs -n1 sed -i -re 's/cargoSha256 = "[^s].../cargoSha256 = "1234/g'
	rg -l "cargoSha256" \| grep "\.nix" \| xargs -n1 sed -i -re 's/cargoSha256 = "sha256-..../cargoSha256 = "sha256-1234/g'

	:def hoogle \x -> return $ ":!hoogle --count=15 \"" ++ x ++ "\""
	:def doc \x -> return $ ":!hoogle --info \"" ++ x ++ "\""
	:set -Wall
	:set -fno-warn-type-defaults -ferror-spans -freverse-errors -fprint-expanded-synonyms
	:set prompt "\ESC[0;32m%s\n\ESC[m[ghci]\ESC[38;5;172mλ \ESC[m"
	:set prompt-cont " \ESC[38;5;172m> \ESC[m"

	(* In Andromeda everything the user writes is "meta-level programming. *)

	(* ML-level natural numbers *)
	mltype rec mlnat =
	\| zero
	\| succ of mlnat
	end

	(* We can use the meta-level numbers to define a program which computes n-fold iterations
	of f. Here we give an explicit type of iterate because the ML-type inference cannot tell

	;; -- lexical-binding: t; --

	;;===[ PERFORMANCE ENHANCEMENTS ]===============================================
	;; See:
	;; https://github.com/hlissner/doom-emacs/wiki/FAQ#how-is-dooms-startup-so-fast
	(defvar file-name-handler-alist-backup file-name-handler-alist)
	(defvar gc-cons-threshold-backup gc-cons-threshold)
	(defvar gc-cons-percentage-backup gc-cons-percentage)

	(setq gc-cons-threshold 402653184