Moving Average Test: Uses Haskell Conduits

AverageByConduit.hs

module Main where

import Control.Applicative ((<$>), (<*>))
import Control.Monad.IO.Class (liftIO)
import Control.Monad.Trans.State (StateT)
import Data.Conduit (($$), (=$=), (=$)
                    , Conduit, Sink, Source
                    , await, yield)
import qualified Data.Conduit.List as CL
import qualified Data.Vector.Unboxed as V

averageV :: V.Vector Int -> Int
averageV vector = (fromIntegral total) `div` (fromIntegral $ V.length vec)
                  where total = V.sum vec :: Int
                        vec = V.slice idx 10 vector
                        idx = V.length vector - 10

source :: Source IO Int
source = CL.sourceList [1..1000]

conduit :: V.Vector Int -> Conduit Int IO Int
conduit vector = do
  val <- await
  case val of
    Nothing -> return ()
    Just n -> do
      let newvector = V.snoc vector n
      if V.length newvector < 10 then conduit newvector else do
        yield $ averageV newvector
        conduit newvector

sink :: Sink Int IO ()
sink = do
  val <- await
  case val of
    Nothing -> return ()
    Just n -> do
      liftIO $ print n
      sink

main :: IO ()
main = do
  let initial = V.fromList []
  source $$ conduit initial =$ sink

conduit-test.cabal

name:                conduit-test
version:             0.1.0.0
synopsis:            Initial project template from stack
description:         Please see README.md
homepage:            https://gist.github.com/pellagic-puffbomb/9239cb57834789886f5c
license:             BSD3
license-file:        LICENSE
author:              Erik Aker
maintainer:          [email protected]
-- copyright:
category:            Web
build-type:          Simple
-- extra-source-files:
cabal-version:       >=1.10

library
  hs-source-dirs:      src
  exposed-modules:     Lib
  build-depends:       base >= 4.7 && < 5
                     , conduit
                     , conduit-combinators
                     , transformers
                     , mtl
                     , resourcet
                     , vector
  default-language:    Haskell2010

executable conduit-test
  hs-source-dirs:      src
  main-is:             Main.hs
  ghc-options:         -threaded -rtsopts -with-rtsopts=-N
  build-depends:       base
                     , transformers
                     , mtl
                     , conduit
                     , conduit-combinators
                     , resourcet
                     , vector
  default-language:    Haskell2010

test-suite new-template-test
  type:                exitcode-stdio-1.0
  hs-source-dirs:      test
  main-is:             Spec.hs

  build-depends:       base
                     , conduit
                     , conduit-combinators
                     , transformers
                     , mtl
                     , resourcet
                     , vector
  ghc-options:         -threaded -rtsopts -with-rtsopts=-N
  default-language:    Haskell2010

source-repository head
  type:     git
  location: https://gist.github.com/pellagic-puffbomb/9239cb57834789886f5c