rahulmutt

#!/usr/bin/env stack
{- stack
     --resolver lts-6.27
     --install-ghc
     runghc
     --package containers
-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE PolyKinds #-}
{-# LANGUAGE DataKinds #-}

i-am-tom

{-# LAnguage FlexibleInstances #-}
{-# LANGuage FunctionalDependencies #-}
{-# LANGUAge GADTs #-}
{-# LANGUAGE UndecidableInstances #-}
module Trolling where

---------------------------------------------------------------------
-- VARIADIC COMPOSITION IN HASKELL (A LA RAMDA.JS).
--
-- In Haskell, we typeically think of the composition operator (or

Gabriella439

* Importance of category theory
    * Answers the question: "What is a *timeless* API?"
        * What does "timeless" mean?
            * Likely to still be relevant years from now
            * Likely to be low maintenance (since unlikely to change)
            * Less likely to be subject to controversy or discussion ("obvious")
    * Examples:
        * Everything Haskell's typeclassopedia (except maybe `Foldable`)
        * Categories / Monoids
            * `(.)` / `id`

puffnfresh

module Payments where

data Customer = Customer { name :: String, age :: Int } deriving (Eq, Ord, Show)

-- I know partial record fields is an anti-pattern, but who's counting?
data Payment
  = Cash { customer :: Customer, amount :: Double }
  | Credit { customer :: Customer, amount :: Double, cardNumber :: Int }
  | Check { customer :: Customer, amount :: Double, routingNumber :: Int, accountNumber :: Int }
  deriving (Eq, Ord, Show)

debasishg

From Theory to Practice: Plug and Play with Succinct Data Structures - Simon Gog, Timo Beller, Alistair Moffat & Matthias Petri (http://arxiv.org/pdf/1311.1249v1.pdf)
Succinct Data Structures for Retrieval and Approximate Membership - Martin Dietzfelbinger and Rasmus Pagh (http://www.itu.dk/people/pagh/papers/bloomier.pdf)
Lecture 17 in Erik Demaine's 6.851 (https://courses.csail.mit.edu/6.851/spring12/lectures/L17.html)
Succinct Data Sstructures by Edward Kmett (https://www.youtube.com/watch?v=uA0Z7_4J7u8)
Succinct Trees in Practice by Diego Arroyuelo, Rodrigo Ćanova, †Gonzalo Navaror Kunihiko Sadakane  http://users.dcc.uchile.cl/~darroyue/papers/alenex2010.pdf

channingwalton

import scala.xml.NodeSeq

object RenderExample {

  object Model {

    trait Toy
    case class Bike extends Toy
    case class Train extends Toy