Zsolt Szende pwm

In response to a request on Reddit, I'm writing up my thoughts on PVP upper bounds. I'm putting this in a Gist since I don't want to start yet another debate on the matter, just provide some information to someone who asked for it. Please don't turn this into a flame war :)

For those unaware: the Package Versioning Policy is a set of recommendations covering how to give version numbers to your packages, and how to set upper and lower bounds on your dependencies.

I'll start by saying: I support completely with the PVP's recommendations on how to assign version numbers. While there are plenty of points in this design space, the PVP is an unobjectionable one, and consistency in the community is good. On multiple occasions, I have reached out to package authors to encourage compliance with this. (However, I've always done so privately, as opposed to a statement on Reddit, as I believe that to be a more likely route to successful convincing.)

The issue aro

Haskell, Stack and Intellij IDEA IDE setup tutorial how to get started

Upon completion you will have a sane, productive Haskell environment adhering to best practices.

Basics

Haskell is a programming language.
Stack is tool for Haskell projects. (similar tools for other languages include Maven, Gradle, npm, RubyGems etc)
Intellij IDEA IDE is a popular IDE.

Install required libraries

sudo apt-get install libtinfo-dev libghc-zlib-dev libghc-zlib-bindings-dev

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:

At work, I just spent the last few weeks exploring and evaluating every format I could find, and my number one criteria was whether they supported sum types. I was especially interested in schema languages in which I could describe my types and then some standard specifies how to encode them using an on-the-wire format, usually JSON.

Swagger represents sum types like Scala does, using subtyping. So you have a parent type EitherIntString with two subtypes Left and Right represented as {"discriminator": "Left", value: 42} and {"discriminator": "Right", value": "foo"}. Unfortunately, unlike in Scala in which the parent type is abstract and cannot be instantiated, in Swagger it looks like the parent type is concrete, so when you specify that your input is an EitherIntString, you might receive {"discriminator": "EitherIntString"} instead of one of its two subtypes.
JSON-schema supports unions, which isn't quite the same thing as sum types because

Thoughts on an InlineDoBind extension

An expression beginning with a left arrow (<-) inside a do block statement is desugared to a monadic binding. This is syntactically a superset of existing Haskell, including extensions. It admits a clean notation that subsumes existing patterns and comes with few downsides.

Examples

do
  f (<- x) (<- y)
-- ===

These links no longer work. Springer have pulled the free plug.

Graduate texts in mathematics

duplicates = multiple editions

A Classical Introduction to Modern Number Theory, Kenneth Ireland Michael Rosen

	#!/bin/bash

	# ---------------------------------------------------------
	# Customizable Settings
	# ---------------------------------------------------------

	MOUNT_POINT="${CASE_SAFE_MOUNT_POINT:-${HOME}/casesafe}"
	VOLUME_PATH="${CASE_SAFE_VOLUME_PATH:-${HOME}/.casesafe.dmg.sparseimage}"
	VOLUME_NAME="${CASE_SAFE_VOLUME_NAME:-casesafe}"
	VOLUME_SIZE="${CASE_SAFE_VOLUME_SIZE:-60g}"

	{-# LANGUAGE GeneralizedNewtypeDeriving #-}

	import Control.Monad.IO.Class
	import Control.Monad.Trans.Class
	import Prelude hiding (log)

	--------------------------------------------------------------------------------
	-- The API for cloud files.
	class Monad m => MonadCloud m where
	saveFile :: Path -> Bytes -> m ()

	{-# LANGUAGE
	UndecidableInstances, RankNTypes, TypeOperators, TypeFamilies,
	StandaloneDeriving, DataKinds, PolyKinds, DeriveFunctor, DeriveFoldable,
	DeriveTraversable, LambdaCase, PatternSynonyms, TemplateHaskell #-}

	import Control.Monad
	import Control.Applicative
	import Data.Singletons.TH

	Purity is a useful construct that forces programmers to consider that the
	environment that they are operating in is unclean, and this introduces
	barriers to formally defining the behaviour of the system comprising
	the program and its environment.

	This file is a [literate Haskell
	file](https://gist.github.com/kisom/3863f17636d99b4f8401) run through
	[pandoc](http://johnmacfarlane.net/pandoc/) to produce a Markdown
	post. There might be a few glitches as I'm still developing a workflow
	in this style.