minoki

{-# LANGUAGE GADTs #-}
{-# LANGUAGE KindSignatures #-}
{-# LANGUAGE TypeOperators, NoStarIsType #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE TypeApplications #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# OPTIONS_GHC -fplugin GHC.TypeLits.Normalise #-}
{-# OPTIONS_GHC -fplugin GHC.TypeLits.KnownNat.Solver #-}
module Sing where
import qualified Data.Singletons.Prelude as S

graninas

Haskeller Competency Matrix

See also List of materials about Software Design in Haskell

	Junior	Middle	Senior	Architect
Haskell level	Basic Haskell	Intermediate Haskell	Advanced Haskell	Language-agnostic
Haskell knowledge scope	Learn you a Haskell	Get programming with Haskell	Haskell in Depth	Knows several languages from different categories
	Get programming with Haskell	Haskell in Depth	Functional Design and Architecture
			[Other books on Software Engineering in Haskell](https://github.com/graninas/software-design-in-haskell#B

serras

Some thoughts on building software

Lately I have been busy reading some new books on Domain Driven Design (DDD) and software architecture -- including a short yet eye-opening one in Python and a great one in F#. At the same time, it seems that more people in the Functional Programming world are looking at more formal approaches to modelling -- some examples here. This has brought some thought from the background of my brain about how we should model, organize, and architect software using the lessons we've learnt from functional programming.

Before moving on, let me be clear about this being just a dump of some thoughts, not always well-defined, definite

ChrisPenner

Optics By Example Cheat Sheets

The following are appendices from Optics By Example, a comprehensive guide to optics from beginner to advanced! If you like the content below, there's plenty more where that came from; pick up the book!

• Operators
• Composition Guide
• Substitution Guide
• Optical Constarints and Types

Operator Cheat Sheet

i-am-tom

{-# LANGUAGE DataKinds               #-}
{-# LANGUAGE PolyKinds               #-}
{-# LANGUAGE TypeOperators           #-}
{-# LANGUAGE UndecidableInstances    #-}
{-# LANGUAGE UnsaturatedTypeFamilies #-}

import GHC.TypeLits
import Prelude hiding (Functor, Semigroup)

type Main = (Fizz <> Buzz) <$> (0 `To` 100)

gaxiiiiiiiiiiii

module NumberPlate where

import Data.List

data Cell = Cell {num :: Int, row :: Int, col :: Int, block :: Int} deriving Eq
data Tree = Node Board [Tree] deriving Show
type Board = [Cell]
type Ploblem = [Int]

instance Show Cell where

Icelandjack

-- https://www.reddit.com/r/haskell/comments/abxem5/experimenting_with_kleisli_instance_of/

{-# Language TypeApplications     #-}
{-# Language RankNTypes           #-}
{-# Language DataKinds            #-}
{-# Language KindSignatures       #-}
{-# Language PolyKinds            #-}
{-# Language TypeOperators        #-}
{-# Language GADTs                #-}
{-# Language TypeFamilies         #-}

Icelandjack

(previous Yoneda blog) (reddit) (twitter)

Yoneda Intuition from Humble Beginnings

Let's explore the Yoneda lemma. You don't need to be an advanced Haskeller to understand this. In fact I claim you will understand the first section fine if you're comfortable with map/fmap and id.

I am not out to motivate it, but we will explore Yoneda at the level of terms and at the level of types.

Icelandjack

import Data.Functor.Yoneda
import Data.Char
import Data.Kind

infixr 5
  ·

type  List :: (Type -> Type) -> Constraint
class List f where

atondwal