Dan Lien danclien

Fire up ghci. Make the text real big. Always show the types for everything as you go!

Takes ~1 hour generally.

Note: if you object to "uncertainty" (evocative of data/value flow possibilities), consider wording like "simultaneously possible values". It's a reference to how the compiler won't know whether Maybe a is a Just a or a Nothing statically. Don't blather at me about dependent types; I know.

Alternate verbiage for uncertainty: product - simultaneous altogetherness, sum - simultaneous singlehood. Also consider what the category theoretic diagrams look like. Can be instructive.

Suggestions taken under advisement.

You should not use the Open SSH client that comes with Git for Windows. Instead, Windows 10 has its own implementation of Open SSH that is integrated with the system. To achieve this:

Start the ssh-agent from Windows Services:

Type Services in the Start Menu or Win+R and then type services.msc to launch the Services window;
Find the OpenSSH Authentication Agent in the list and double click on it;
In the OpenSSH Authentication Agent Properties window that appears, choose Automatic from the Startup type: dropdown and click Start from Service status:. Make sure it now says Service status: Running.

Configure Git to use the Windows 10 implementation of OpenSSH by issuing the following command in Powershell:

git config --global core.sshCommand C:/Windows/System32/OpenSSH/ssh.exe

	{-# LANGUAGE ExistentialQuantification, RankNTypes #-}
	{-# LANGUAGE InstanceSigs #-}
	module CoYoneda where

	import Data.IORef
	import Data.Set (Set, map)
	import Control.Monad (liftM)

	--------------------------------------------------------------------------------
	-- Yoneda

	import scalaz._
	import Scalaz._
	import Free._

	/** "Pure" interactions with a console. */
	sealed trait Console[+A]
	case class GetLine[A](k: String => A) extends Console[A]
	case class PutLine[A](s: String, a: A) extends Console[A]

	object Console {

	$ sudo gem install guard
	$ sudo gem install guard-shell

	links:
	- https://github.com/guard/guard
	- https://github.com/guard/guard-shell

	Create a file named "Guardfile" in the root of the project and put the following lines in it:

	guard :shell do

	#!/usr/bin/env bash

	# Utility functions

	## Logging
	log_debug() {
	if [ "$OPT_VERBOSE" = true ]; then
	echo "$(tput setaf 5)Debug: $(tput sgr 0)" "$@"
	fi
	}