David M. Johnson dmjio

WELCOME

We're stoked you've chosen to join us. If you're successful, you'll be joining a team that is focused on technical excellence and continuous improvement. We take great care to produce well-structured, well-tested, maintainable code. To be successful, you'll need to demonstrate that you do as well.

Our expectations are that this exercise should take you no longer than 4 hours to complete (and hopefully much less). If it takes you much longer than that to get to a working solution, you might not be the right candidate for this role.

INSTRUCTIONS

Complete the short version of the Big 5 test and save your results as text.
Create a new git repository for your code.
Write a utility that parses the textual results of your test into the following format. Note that you'll need to include your email, which doesn't appear in the output of your Big 5 test. Feel free to use intermediary data structures and useful libraries.

Reddit discussion.

Disclaimer 1: Type classes are great but they are not the right tool for every job. Enjoy some balance and balance to your balance.

Disclaimer 2: I should tidy this up but probably won’t.

Disclaimer 3: Yeah called it, better to be realistic.

Type classes are a language of their own, this is an attempt to document features and give a name to them.

Installation of NixOS with encrypted root

These are my notes on instaling NixOS 16.03 on a Lenovo ThinkPad X1 Carbon (4th generation) with an encrypted root file system using UEFI.

Most of this is scrambled from the following pages:

	{-# LANGUAGE MultiParamTypeClasses #-}
	{-# LANGUAGE FlexibleInstances #-}
	{-# LANGUAGE OverloadedStrings #-}
	{-# LANGUAGE DataKinds #-}
	{-# LANGUAGE DeriveGeneric #-}
	{-# LANGUAGE TypeOperators #-}

	module Sand where

	import Data.Aeson

	{ pkgs ? import <nixpkgs> {}}:


	let
	texpkgs = pkgs.texlive.combine {
	inherit (pkgs.texlive) scheme-small latexmk;
	};
	in
	pkgs.stdenv.mkDerivation {
	name = "mbd";

	-- RHS size: {terms: 254, types: 135, coercions: 0}
	Xeno.$wparse [InlPrag=[0]]
	:: GHC.Prim.Addr#
	-> GHC.ForeignPtr.ForeignPtrContents
	-> GHC.Prim.Int#
	-> GHC.Prim.Int#
	-> ()
	[GblId,
	Arity=4,
	Str=DmdType <L,U><L,U><L,U><S,U>,

	# This expression builds a copy of Twitter Bootstrap CSS but with every rule embedded inside a CSS selector of
	# your choice. This makes it easy to embed a Bootstrap-themed component in a site that doesn't use Bootstrap.
	#
	# Usage
	# * Install nix from https://nixos.org/nix/ (it's a fancy package manager that won't mess up your system)
	# * Save this file to `scoped-bootstrap.nix`
	# * With nix stuff on your PATH, run `nix-build scoped-bootstrap.nix`
	# * The result will be in `./result/` (a symlink). Copy to desired location.
	# * If you don't want to keep `nix`: `rm -rf /nix`

	{-# LANGUAGE DeriveFunctor #-}
	module Bidi where

	-- For 'guard'.
	import Control.Monad
	-- We use Cofree to represent type-annotated terms.
	import Control.Comonad.Cofree
	import Data.Functor.Classes
	-- We use Fix to represent unannotated terms.
	import Data.Functor.Foldable

	{-# LANGUAGE DataKinds #-}
	{-# LANGUAGE FlexibleInstances #-}
	{-# LANGUAGE FunctionalDependencies #-}
	{-# LANGUAGE KindSignatures #-}
	{-# LANGUAGE MultiParamTypeClasses #-}
	{-# LANGUAGE PolyKinds #-}
	{-# LANGUAGE RankNTypes #-}
	{-# LANGUAGE ScopedTypeVariables #-}
	{-# LANGUAGE TypeFamilies #-}
	{-# LANGUAGE TypeSynonymInstances #-}

	module Main where

	{-
	Here is a real---if not particularly interesting---interaction with this server:

	[gdritter@armilla ~]$ ssh -p 9999 localhost incr
	ok.
	[gdritter@armilla ~]$ ssh -p 9999 localhost incr
	ok.
	[gdritter@armilla ~]$ ssh -p 9999 localhost double