| type Graph[A] = Map[A, Set[A]] | |
| def bfs[A](graph: Graph[A], start: A, end: A): Option[List[A]] = | |
| import scala.collection.immutable.ListSet | |
| @annotation.tailrec | |
| def bfsTR(remaining: List[A], visited: ListSet[A]): Option[List[A]] = | |
| remaining match | |
| case Nil => None | |
| case h :: t if visited(h) => bfsTR(t, visited) | |
| case h :: _ if h == end => Some((visited + h).toList) |
| {-# LANGUAGE GADTs #-} | |
| class IOEffect x where | |
| runIOEffect :: x a -> IO a | |
| data M a where | |
| Pure :: a -> M a | |
| Ap :: M (a -> b) -> M a -> M b | |
| Bind :: M a -> (a -> M b) -> M b | |
| M :: IOEffect x => x a -> M a |
May 28, 2014
This code is a companion to the APIcon presentation Real-World Functional Programming by @jearldouglas and @kelleyrobinson. The slides are available here.
In this code, we compare imperative and functional implementations of a withdraw function that might be used in a banking ATM.
| trait Container[A] { | |
| def has(a: A): Boolean | |
| } | |
| implicit def listContainer[A](xs: List[A]): Container[A] = | |
| new Container[A] { | |
| override def has(a: A): Boolean = xs.contains(a) | |
| } |
| // -*- mode: Scala;-*- | |
| // Filename: k.scala | |
| // Authors: lgm | |
| // Creation: Wed Dec 28 14:52:27 2011 | |
| // Copyright: Not supplied | |
| // Description: | |
| // ------------------------------------------------------------------------ | |
| import scala.collection.mutable.HashMap | |
| import scala.util.continuations._ |
| package await | |
| import java.util.concurrent.Callable | |
| import java.util.concurrent.Executors | |
| object BlockingDemo extends App { | |
| val execSvc = Executors.newSingleThreadExecutor() | |
| val worker = new MeaningOfLife() |
| package com.earldouglas.remoteakka | |
| import akka.actor.Actor | |
| import akka.actor.Actor._ | |
| case object Greeting | |
| case class Jar(val bytes: Array[Byte]) | |
| case class RegisterRemote(val name: String, val className: String) | |
| object Runner { |