tonyday567

bird
----

> {-# LANGUAGE GADTs, TypeSynonymInstances #-}
> module ArcChallenge where
>
> import Control.Applicative
> import Control.Applicative.Error (Failing (..))
> import Control.Monad (ap)

tonyday567

In this gist we will first show that we can beat the arc challenge
(http://www.paulgraham.com/arcchallenge.html), and then build the library that
shows how we did it. This gist is Literate Haskell and is of course executable. The packages needed are happstack-server and applicative-extras, installable using cabal.

Let's start with some imports (for now, you can ignore these)

> {-# LANGUAGE GADTs, TypeSynonymInstances #-}
> module ArcChallenge where
>
> import Control.Applicative

tonyday567

literate haskell test

> {-# LANGUAGE RankNTypes, KindSignatures #-}

> module ArcChallenge where
>
> import Control.Applicative

> module ArcChallenge where
>

tonyday567

body {
  font-family: Helvetica, arial, sans-serif;
  font-size: 14px;
  line-height: 1.6;
  padding-top: 10px;
  padding-bottom: 10px;
  background-color: white;
  padding: 30px; }

body > *:first-child {

tonyday567

{-# LANGUAGE ExistentialQuantification, RankNTypes #-}

module Scanl where

import           Control.Foldl (Fold(..))
import           Data.Foldable (Foldable)
import qualified Data.Foldable as F
import           Data.Traversable

scan :: (Foldable f) => Fold a b -> f a -> [b]

tonyday567

{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE DefaultSignatures #-}

import GHC.Generics
import Control.Applicative
import Data.Text.Encoding
import           Data.Aeson
import           Data.Aeson.Types
import qualified Data.ByteString as B
import qualified Data.ByteString.Lazy as LB

tonyday567

tRemote :: Int -> IO ()
tRemote n = do
    backend0 <- initializeBackend host portSlave rtable
    node0 <- newLocalNode backend0
    backend <- initializeBackend host portMaster rtable
    node <- newLocalNode backend
    Node.runProcess node (remotePipe' n (Node.localNodeId node0))
  where
    rtable :: RemoteTable
    rtable = __remoteTable initRemoteTable

tonyday567

vcStd :: Managed (View C.ByteString, Controller C.ByteString)
vcStd = ((,) <$> pure (contramap show MVC.stdoutLines) <*> fmap C.pack <$> MVC.stdinLines)

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{-# language OverloadedStrings #-}
{-# LANGUAGE RankNTypes #-}

module TestMVC where

import Control.Category hiding ((.),id)
import qualified MVC.Prelude as MVC
import MVC
import qualified Pipes.Prelude as Pipes
import Control.Applicative

tonyday567

{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE FlexibleInstances #-}

module Pipes.Getter where