Alexander Granin graninas

Appendix to Software Design in Haskell

List of materials on Software Design in Haskell

Other resources that are good, but not necessarry about Software Design

Testing

Testing | Monday Morning Haskell

Software Design Showcase Projects in Haskell

(WIP)

Automatic White-Box Testing with Free Monads | Alexander Granin
- Description: Article and showcase project about an approach to whitebox testing. Describes the idea of recordable and replayable business scenarios based on the Free Monad approach.
- Design Approach: [Free Monads]
- Technologies: [free, aeson]
- Teaches for: How to make a Free monad based business logic recordable and replayable. How to use the recordings for automatic whitebox testing. How to configure this system to do integration testing.

The Problem

Defining records in Haskell causes accessor functions for the record's fields to be defined. There is no seperate namespace for these accessor functions.

The Goal

Be able to

use records in Haskell, which share field names.
use lenses for accessing these fields

An Opinionated Comparison of Software Design Approaches in Haskell

#Knuth arrows in C++ metaprogramming.

Two implementations of Knuth's arrows using constexpr and template metaprogramming.

Constexpr Knuth arrows
Template Knuth arrows

#include <iostream>

constexpr int sum (int a, int b)
{
	return a + b;
}

constexpr int ediv (int a, int b)
{


	data User = User
	{ firstName :: String
	, secondName :: String
	}

	-- The User data type has field firstName, it's a string.

	-- firstName :: User -> String
	-- secondName :: User -> String

	//
	// See https://github.com/louthy/language-ext
	//

	using System;
	using System.IO;
	using System.Linq;
	using System.Threading.Tasks;
	using LanguageExt;
	using static LanguageExt.Prelude;

	{
	"entries": [
	[
	0,
	{
	"tag": "Normal"
	},
	"GenerateGUIDEntry",
	"{\"contents\":{\"guid\":\"662ed4a1-950b-48cd-a91d-1091342070d9\"},\"tag\":\"GenerateGUIDEntry\"}"
	],