aavogt’s gists

aavogt / Experiment.hs

Last active May 1, 2016 17:55

applying layout modifiers to existentially quantified layouts

	{-# LANGUAGE TypeOperators #-}
	{-# LANGUAGE ScopedTypeVariables #-}
	{-# LANGUAGE RankNTypes #-}
	import XMonad
	import Data.Constraint

	-- supplied: seems to be the pattern for layout modifier instances
	typicalEntailment :: Read (l' a) :- Read (Mirror l' a)
	typicalEntailment = Sub Dict

aavogt / A.hs

Created April 1, 2016 23:18

	{-# LANGUAGE FlexibleInstances #-}
	{-# LANGUAGE OverlappingInstances #-}
	{-# LANGUAGE GADTs #-}
	module A where

	a0 :: EqBox A
	a0 = EqBox A

	data EqBox a where EqBox :: Eq a => a -> EqBox a

aavogt / Insert.hs

Created March 23, 2016 20:09

overload Map and Set insert

+{-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+-- | properly overload M.insert and S.insert
+module Insert where
+import Data.Proxy

aavogt / Main.hs

Created March 5, 2016 02:42

	{-# LANGUAGE CPP #-}
	{-# LANGUAGE FlexibleContexts #-}
	{-# LANGUAGE FlexibleInstances #-}
	{-# LANGUAGE MultiParamTypeClasses #-}
	{-# LANGUAGE DataKinds #-}
	{-# LANGUAGE KindSignatures #-}
	{-# LANGUAGE TypeFamilies #-}
	import GHC.TypeLits
	import Data.Proxy

aavogt / CountM.hs

Created February 29, 2016 20:22

wrap a data in Just if it is missing

	{-# LANGUAGE TypeOperators #-}
	{-# LANGUAGE UndecidableInstances #-}
	{-# LANGUAGE FlexibleContexts #-}
	{-# LANGUAGE ScopedTypeVariables #-}
	{-# LANGUAGE TypeFamilies #-}
	{-# LANGUAGE DataKinds #-}
	{-# LANGUAGE FlexibleInstances #-}
	{-# LANGUAGE FunctionalDependencies #-}
	{-# LANGUAGE MultiParamTypeClasses #-}
	module CountM where

aavogt / Main.hs

Created February 28, 2016 14:03

lookup fields in nested records as if they are actually flat (by enumerating all paths through the nested records)

	{-# LANGUAGE ConstraintKinds #-}
	{-# LANGUAGE DataKinds #-}
	{-# LANGUAGE FlexibleContexts #-}
	{-# LANGUAGE FlexibleInstances #-}
	{-# LANGUAGE FunctionalDependencies #-}
	{-# LANGUAGE GADTs #-}
	{-# LANGUAGE KindSignatures #-}
	{-# LANGUAGE MultiParamTypeClasses #-}
	{-# LANGUAGE OverlappingInstances #-}
	{-# LANGUAGE PolyKinds #-}

aavogt / C.hs

Created February 22, 2016 18:10

reify does not report the use of PromotedT

	{-# LANGUAGE DataKinds #-}
	{-# LANGUAGE KindSignatures #-}
	module C where

	class C (a :: Bool)

	instance C True
	instance C 'False -- ' syntax doesn't make a difference

aavogt / M.hs

Created February 17, 2016 19:59

maintaining type inference when repeating information in an instance head

	{-# LANGUAGE NoMonomorphismRestriction #-}
	{-# LANGUAGE ConstraintKinds #-}
	{-# LANGUAGE UndecidableInstances #-}
	{-# LANGUAGE TypeFamilies #-}
	{-# LANGUAGE FlexibleInstances #-}
	{-# LANGUAGE MultiParamTypeClasses #-}
	module M where
	import Prelude hiding ((.), id)

	type Cat a b c = (SameKs a b c, C a b c)

aavogt / CategoryIsh.hs

Created February 17, 2016 04:29

a newtype for HLists of functions

	{-# LANGUAGE DataKinds #-}
	{-# LANGUAGE FlexibleInstances #-}
	{-# LANGUAGE KindSignatures #-}
	{-# LANGUAGE MultiParamTypeClasses #-}
	{-# LANGUAGE NoMonomorphismRestriction #-}
	{-# LANGUAGE PartialTypeSignatures #-}
	{-# LANGUAGE TypeFamilies #-}
	{-# LANGUAGE TypeOperators #-}
	{-# LANGUAGE UndecidableInstances #-}
	{-# OPTIONS_GHC -fno-warn-partial-type-signatures #-}

aavogt / ExtensibleMappend.hs

Last active February 9, 2016 07:40

	{-# LANGUAGE PolyKinds #-}
	{-# LANGUAGE DataKinds, FlexibleContexts, TemplateHaskell, TypeFamilies, TypeOperators #-}
	import Data.Extensible
	import Data.Monoid
	import Control.Monad.Identity

	mkField "a b"

	nilR :: Comp First (Field Identity) :* '[]
	nilR = Nil

Adam Vogt aavogt