jbpotonnier’s gists

jbpotonnier / Friends.hs

Created July 5, 2013 12:37

Atelier Haskell

	module Friends where

	data Relation = Friend \| Cousin \| Professor deriving (Show, Eq)
	data Person = Person String deriving (Show, Eq)
	data Fact = Fact Relation (Person, Person) deriving (Show, Eq)
	data Graph = Graph [Fact] deriving Show

	areFriends :: Graph -> Person -> Person -> Bool
	areFriends (Graph facts) person1 person2 =
	(not . null) [(p1, p2) \| Fact Friend (p1, p2) <- facts, p1 == person1 && p2 == person2]

jbpotonnier / Reco.hs

Last active December 19, 2015 09:59

Recommend products based on sales. There is an approximation when sorting by sales, considering the wholes sales, when only the sales of people having bought the same product should be used. The data structure could be easily implemented in Redis ;)

	module Reco where

	import Prelude hiding (product)
	import qualified Data.Set as Set
	import Data.Set(Set)
	import qualified Data.Map as Map
	import Data.Map(Map)
	import Data.List(sortBy)
	import Data.Ord (comparing)

jbpotonnier / Main.hs

Created September 16, 2013 21:08

The code I wrote as an exercise to answer Zalora job offer.

	{-# LANGUAGE QuasiQuotes #-}
	{-# LANGUAGE OverloadedStrings #-}

	module Main where

	import Data.List (intercalate)
	import Data.Maybe (fromMaybe)

	import Network.HTTP.Conduit (simpleHttp)
	import Control.Concurrent.Async (mapConcurrently)

jbpotonnier / events.js

Last active December 26, 2015 08:59

Fun with Knockout and ajax calls. Display and update the last events on Github.

	var events = ko.mapping.fromJS([]);

	ko.applyBindings({
	events: events,
	onRowClicked: function (row) {
	// modify model to update UI. Will be re-updated by next ajax call :P
	row.actor.login("FOO");
	}
	});

jbpotonnier / gists.html

Created October 24, 2013 21:47

	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="UTF-8">
	<title>Gists</title>
	<link type="text/css" rel="stylesheet" href="style.css">
	<script type='text/javascript' src='lib/zepto.min.js'></script>
	<script type='text/javascript' src='lib/knockout-2.3.0.js'></script>
	<script type='text/javascript' src='lib/knockout.mapping-latest.js'></script>
	</head>

jbpotonnier / FilterAndRemoveEmpty.hs

Last active December 27, 2015 17:39

Filter tree using a predicate, like the widgets to help finding file in directories.

	module FilterTree where

	import Data.Maybe (mapMaybe)

	data Tree a b = Leaf a
	\| Node a [Tree a b]
	deriving Show

	filterTree :: (a -> Bool) -> Tree a b -> Maybe (Tree a b)
	filterTree p tree =

jbpotonnier / Json.hs

Created November 15, 2013 13:34

	{-# LANGUAGE FlexibleInstances, MultiParamTypeClasses #-}
	{-# LANGUAGE DeriveGeneric #-}

	module Json where

	import Test.SmallCheck.Series
	import GHC.Generics

	import Data.List (intercalate)
	import qualified Text.ParserCombinators.Parsec.Token as Token

jbpotonnier / Polynomial.hs

Last active December 28, 2015 18:39

	{-# LANGUAGE FlexibleInstances, MultiParamTypeClasses #-}
	{-# LANGUAGE DeriveGeneric #-}

	module Polynomial where

	import Test.SmallCheck.Series (Serial)
	import GHC.Generics (Generic)

	import qualified Text.ParserCombinators.Parsec as Parsec
	import Text.ParserCombinators.Parsec (ParseError, Parser, sepBy1)

jbpotonnier / ghci

Last active January 3, 2016 12:29

Some tools to use Haskell in a shell pipe. ex: cat stats.dat | hask 'maplines (nth 1 |> to_float) |> maximum'

	import Control.Category ((>>>))

	let io h = interact $ (++"\n") . show . h
	let maplines h = map (h . words) . lines
	let to_float = read :: String -> Float
	let nth = flip (!!)
	let (\|>) = (>>>) :: (a -> b) -> (b -> c) -> (a -> c)

jbpotonnier / Connector.hs

Last active August 29, 2015 13:56

Using semaphore to allocate resources.

	import Network (withSocketsDo, accept, listenOn, PortID(PortNumber))
	import Control.Concurrent (forkIO)
	import System.IO (Handle, hClose, hGetLine, hSetBuffering, BufferMode (..))
	import Control.Applicative ((<$>), (<*>))
	import Control.Monad (forever)
	import Control.Monad.STM (atomically)
	import Control.Concurrent.STM (STM)
	import Control.Concurrent.STM.TChan (TChan, newTChan, writeTChan, readTChan)
	import Control.Concurrent.STM.TVar (TVar, newTVar, writeTVar, readTVar)
	import Control.Concurrent.STM.SSem (SSem)

Jean-Baptiste Potonnier jbpotonnier