Ludvig Hult el-hult

el-hult / comonadVectorDiff.hs

Created May 7, 2019 19:46

Finding right angles between 2D vectors using comonads

	-- This is using a haskell comonad to find right angles between given geometrical vectors
	-- The code is kind of overkill, but it is a cute showcase of comonads


	-- a FocusSet. One element in Focus, and all other elements in a list.
	data Fs a = Fs a [a] deriving (Show)

	instance Functor Fs where
	fmap fun (Fs k l) = Fs (fun k) (map fun l)

el-hult / comonadVectorDiff.hs

Created May 7, 2019 19:46

Finding right angles between 2D vectors using comonads

	-- This is using a haskell comonad to find right angles between given geometrical vectors
	-- The code is kind of overkill, but it is a cute showcase of comonads


	-- a FocusSet. One element in Focus, and all other elements in a list.
	data Fs a = Fs a [a] deriving (Show)

	instance Functor Fs where
	fmap fun (Fs k l) = Fs (fun k) (map fun l)

el-hult / gameOfLife.hs

Created May 7, 2019 19:37

1D Game of Life in the terminal

	-- http://blog.sigfpe.com/2006/12/evaluating-cellular-automata-is.html
	-- The above post learned me about this neat comonad instance! :D

	data U x = U [x] x [x]

	right,left:: U x -> U x -- shift focus of the zipper
	right (U a b (c:cs)) = U (b:a) c cs
	left (U (a:as) b c) = U as a (b:c)

	-- the zipper is a functor

el-hult / day4.html

Last active December 27, 2018 14:06

advent of code 2017 day 4 html page.

	<!doctype html><html><head><meta charset="utf-8"/><script>

	const isValid = raw => {
	const words = raw.split(/\s+/)
	// writeToBody("raw: " + raw)
	// writeToBody("words: " + words)
	const checker = (prevAcc, nextWord) => {
	const acc = { set: prevAcc.set, count: prevAcc.count };
	if( acc.set.has(nextWord) ) { acc.count = acc.count + 1 }
	else { acc.set.add(nextWord) }