Afonso Matos afonsomatos

Undo/Redo is one of those features of an application that you almost always need to have if you are building serious GUI tools for people to do work.

The best way to look at undo/redo is two stacks of operations the user has performed:

The Undo stack is the "history" of what they've done
The redo stack is the breadcrumbs back to the initial state before they started undoing

This is the sequence of steps to follow to create a root gh-pages branch. It is based on a question at [SO]

cd /path/to/repo-name
git symbolic-ref HEAD refs/heads/gh-pages
rm .git/index
git clean -fdx
echo "My GitHub Page" &gt; index.html

	/*
	An Alias Method implementation written in JavaScript

	Copyright (c) 2016 Hans Jorgensen

	Permission is hereby granted, free of charge, to any person obtaining a copy of
	this software and associated documentation files (the "Software"), to deal in
	the Software without restriction, including without limitation the rights to use,
	copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
	Software, and to permit persons to whom the Software is furnished to do so,

	{-# LANGUAGE OverloadedStrings #-}

	import GHC.Exts ( IsString(..) )

	data Foo = A \| B \| Other String deriving Show

	instance IsString Foo where
	fromString "A" = A
	fromString "B" = B
	fromString xs = Other xs