Gabriella439

import Numeric.Natural (Natural)

import qualified Data.Semigroup

-- | @fibonacci n@ computes the @nth@ fibonacci number efficiently using infinite
-- precision integer arithmetic
-- 
-- Try @fibonacci 1000000@
fibonacci :: Natural -> Natural
fibonacci n = x01 (Data.Semigroup.mtimesDefault n m)

themattchan

{-# LANGUAGE DeriveFunctor #-}
import Control.Arrow ((&&&))
import Data.Bifunctor

-- Recursion Schemes for Dynamic Programming
-- Kabanov and Vene, Mathematics for Program Construction 2006

-- Basic stuff

newtype Mu f = In { out :: f (Mu f) }

beesandbombs

int[][] result;
float t, c;

float ease(float p) {
  return 3*p*p - 2*p*p*p;
}

float ease(float p, float g) {
  if (p < 0.5) 
    return 0.5 * pow(2*p, g);

marcosh

module Application where

import Data.Profunctor

newtype Application request response =  Application {unApplication :: request -> IO response}

instance Profunctor Application where
    dimap actOnRequest actOnResponse application = Application $ (fmap actOnResponse) . (unApplication application) . actOnRequest

buggymcbugfix

Writing a paper, according to SPJ

Source: https://www.cis.upenn.edu/~sweirich/icfp-plmw15/slides/peyton-jones.pdf

1. Abstract (4 sentences, write last; used by program committee members to decide which papers to read)
   1. State the problem
   2. Say why it’s an interesting problem
   3. Say what your solution achieves
   4. Say what follows from your solution
2. Introduction (1 page)

bradparker

module Main where

import Data.Bool (bool)
import Control.Monad ((<=<))
import Control.Monad.State (State, evalState, get, put)
import Data.Char (isSpace)
import Data.Foldable (traverse_)
import Data.Functor.Compose (Compose(Compose, getCompose))
import Data.Functor.Const (Const(Const, getConst))
import Data.Functor.Product (Product(Pair))

jaspervdj

--------------------------------------------------------------------------------
-- Is List or NonEmpty "simpler"?  Neither:

type NonEmpty a = Fix (Compose ((,) a) Maybe)
type List     a = Fix (Compose Maybe ((,) a))

--------------------------------------------------------------------------------

newtype Fix f = Fix {unFix :: f (Fix f)}

friedbrice

var danielsLensTalk = {
    recordId: 0,
    creation: {
        user: '[email protected]',
        moment: {
            date: {
                year: 2019,
                month: 5,
                day: 29
            },