Akii’s gists

Akii / ChunkChan.hs

Created March 17, 2019 18:41

	chunkChan :: Int -> Int -> TChan a -> IO [a]
	chunkChan numItems timeoutSeconds chan = do
	maybeRead <- timeout (timeoutSeconds * 60 * 1000) . atomically $ replicateM numItems (readTChan chan)
	case maybeRead of
	Just as -> return as
	Nothing -> do
	as <- emptyChannel chan
	if null as
	then chunkChan numItems timeoutSeconds chan
	else return as

Akii / WhyTho.hs

Created December 6, 2018 17:29

	instance (Ord a) => Ord [a] where
	compare [] [] = EQ
	compare [] (_:_) = LT
	compare (_:_) [] = GT
	compare (x:xs) (y:ys) = case compare x y of
	EQ -> compare xs ys
	other -> other

Akii / gist:3f792f149b23a23dca0ecab9230e0569

Created November 29, 2018 18:21

	-- This is part of a pipeline that continously produces `ev`s
	-- Essentially this is a fold or scan. I call `a` a "projection" of a series of `ev`s
	projectionConsumer :: IORef a -> (ev -> a -> a) -> Consumer ev IO ()
	projectionConsumer ref f = for cat $ modifyIORef' ref . f

	-- projectionBConsumer :: IORef b -> (ev -> b -> b) ...

	-- I now have this issue of composing multiple of these folds
	-- What I resorted to is something like this
	someOtherProjection :: IORef a -> IORef x -> IO ()

Akii / SomeTemplate.elm

Created November 28, 2018 22:33

	itemView : Item -> Html Msg
	itemView item =
	tr []
	[ td [ class "item-id" ] [ text ("#" ++ item.id) ]
	, td [ class "item-name" ] [ text item.name ]
	]

Akii / IQR.hs

Created November 20, 2018 17:54

Akii / gist:2bd7efa8fac1697ea5611f1368fa4424

Created November 16, 2018 10:03

	{-# LANGUAGE ConstraintKinds #-}
	{-# LANGUAGE DataKinds #-}
	{-# LANGUAGE FlexibleInstances #-}
	{-# LANGUAGE GADTs #-}
	{-# LANGUAGE ScopedTypeVariables #-}
	{-# LANGUAGE TypeApplications #-}
	{-# LANGUAGE TypeFamilies #-}
	{-# LANGUAGE TypeOperators #-}
	{-# LANGUAGE UndecidableInstances #-}

Akii / ThisIsAmazing.hs

Created November 16, 2018 09:56

	type family All (c :: Type -> Constraint)
	(ts :: [Type]) :: Constraint where
	All c '[] = ()
	All c (x ': xs) = (c x, All c xs)

Akii / NT.hs

Created November 12, 2018 16:16

	newtype NT = NT String

	foo :: Maybe NT
	foo = Just (NT "test")

	bar :: Maybe NT -> Maybe String
	bar = undefined -- ??? how to do this?

	-- this would work but it verbose for multiple data constructors
	bar (Just $ NT s) = Just s

Akii / Intro.yaml

Created November 12, 2018 12:51

	title: Elescore;DB FaSta API;Compensation;Outage
	author: Philipp Maier
	summary: "
	<p>Elescore (elevator + scoring), a platform that tracks elevator disruptions, integrates multiple external data sources.
	One of these sources is the DB FaSta API: Elevator status for all stations operated by Deutsche Bahn.</p>
	<p>
	In the past, this API has had several major outages resulting in corruption of data.
	Using event sourcing and statistics, I was able to detect outages and compensate them.</p>"
	tags: Haskell, Statistics, 1.5 x IQR, Event-Sourcing, Stream Processing

Akii / gist:1e6449b2831810775a4906c2b04c85b3

Created November 11, 2018 15:56