Flávio Luiz Mendes flmendes

10 Scala One Liners to Impress Your Friends

Here are 10 one-liners which show the power of scala programming, impress your friends and woo women; ok, maybe not. However, these one liners are a good set of examples using functional programming and scala syntax you may not be familiar with. I feel there is no better way to learn than to see real examples.

Updated: June 17, 2011 - I'm amazed at the popularity of this post, glad everyone enjoyed it and to see it duplicated across so many languages. I've included some of the suggestions to shorten up some of my scala examples. Some I intentionally left longer as a way for explaining / understanding what the functions were doing, not necessarily to produce the shortest possible code; so I'll include both.

1. Multiple Each Item in a List by 2

The map function takes each element in the list and applies it to the corresponding function. In this example, we take each element and multiply it by 2. This will return a list of equivalent size, compare to o

Nginx + Unicorn for Rails on Rackhub

Description:

This script enables you to launch your Rails application in production environment (port:80) with Nginx and Unicorn.

Installation:

Please make sure that your Gemfile in your rails application includes unicorn.

	package vmarcinko.undertow;

	import io.undertow.Handlers;
	import io.undertow.Undertow;
	import io.undertow.server.HttpHandler;
	import io.undertow.server.handlers.PathHandler;
	import io.undertow.server.handlers.RedirectHandler;
	import io.undertow.server.handlers.resource.FileResourceManager;
	import io.undertow.servlet.Servlets;
	import io.undertow.servlet.api.DeploymentInfo;

	\n
	============= HOST: ==========\n
	\n
	local_ip: %{local_ip}\n
	local_port: %{local_port}\n
	remote_ip: %{remote_ip}\n
	remote_port: %{remote_port}\n
	\n
	======= CONNECTION: ==========\n
	\n

	{
	"color_scheme": "Packages/Color Scheme - Default/Monokai Bright.tmTheme",
	"ensure_newline_at_eof_on_save": true,
	"file_exclude_patterns":
	[
	"*.DS_store",
	"*.gem",
	"*.gz",
	"*.jar",
	"*.sassc",

	#!/bin/sh
	exec scala -savecompiled "$0" "$@"
	!#

	import java.awt._
	import java.io._
	import javax.imageio.ImageIO

	if (args.length != 1) {
	println(" Usage: script filename")

	package core.dao

	import play.api.Logger
	import reactivemongo.core.commands.LastError
	import reactivemongo.core.errors.DatabaseException
	import scala.concurrent.Future

	import core.db.MongoHelper
	import core.exceptions._

	package daos

	import scala.concurrent.ExecutionContext
	import scala.concurrent.Future
	import play.api.Play.current
	import play.modules.reactivemongo._
	import reactivemongo.api._
	import reactivemongo.api.indexes._
	import reactivemongo.bson._
	import reactivemongo.bson.handlers.BSONReader

	// simple example of the cake pattern

	// abstract DAO trait
	trait Repository[A, B]{
	// saves an entity, returns an ID
	def save(entity: A): B
	// more features..
	}

	trait RdbmsRepository extends Repository[MyUserCaseClass, Long]{

	/*********************************************************
	* Setup Domain object, repositories and service objects *
	********************************************************/
	// Identity.scala
	case class Identity(id: Int = 0, var slug: String, var email: String, references: Symbol)

	// IdentityRepostiory.scala: my interface that isolates concrete instances
	trait IdentityRepository {
	def findBySlug(slug: String): Option[Identity]
	def findByEmail(email: String): Option[Identity]