Abel Terefe abelbryo

Applied Functional Programming with Scala - Notes

1. Mastering Functions

A function is a mapping from one set, called a domain, to another set, called the codomain. A function associates every element in the domain with exactly one element in the codomain. In Scala, both domain and codomain are types.

val square : Int => Int = x => x * x

	<!DOCTYPE HTML>
	<html lang="en-US">
	<head>
	<meta charset="UTF-8">
	<title>test upload by chunk</title>
	</head>
	<body>
	<input type="file" id="f" />

	<script src="script.js"></script>

	/*
	* A function that converts a PostGIS query into a GeoJSON object.
	* Copyright (C) 2012 Samuel Giles <[email protected]>
	*
	* This program is free software: you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation, either version 3 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,

	-- show running queries (pre 9.2)
	SELECT procpid, age(clock_timestamp(), query_start), usename, current_query
	FROM pg_stat_activity
	WHERE current_query != '<IDLE>' AND current_query NOT ILIKE '%pg_stat_activity%'
	ORDER BY query_start desc;

	-- show running queries (9.2)
	SELECT pid, age(clock_timestamp(), query_start), usename, query
	FROM pg_stat_activity
	WHERE query != '<IDLE>' AND query NOT ILIKE '%pg_stat_activity%'

	#!/usr/bin/perl -T
	# $Id: makebib.perl,v 1.18 2006/02/06 05:34:04 t Exp $
	#
	# This program is free software; you can redistribute it and/or modify
	# it under the terms of the GNU General Public License as published by
	# the Free Software Foundation; either version 2 of the License, or
	# (at your option) any later version.
	#
	# This program is distributed in the hope that it will be useful,
	# but WITHOUT ANY WARRANTY; without even the implied warranty of

	package slicks.docs.dao

	import scala.slick.driver.PostgresDriver.simple._
	import scala.slick.driver._


	trait Profile {
	val profile: JdbcProfile
	}

	var mediaJSON = { "categories" : [ { "name" : "Movies",
	"videos" : [
	{ "description" : "Big Buck Bunny tells the story of a giant rabbit with a heart bigger than himself. When one sunny day three rodents rudely harass him, something snaps... and the rabbit ain't no bunny anymore! In the typical cartoon tradition he prepares the nasty rodents a comical revenge.\n\nLicensed under the Creative Commons Attribution license\nhttp://www.bigbuckbunny.org",
	"sources" : [ "http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4" ],
	"subtitle" : "By Blender Foundation",
	"thumb" : "images/BigBuckBunny.jpg",
	"title" : "Big Buck Bunny"
	},
	{ "description" : "The first Blender Open Movie from 2006",
	"sources" : [ "http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/ElephantsDream.mp4" ],



	import scala.annotation.tailrec

	object Backtracking {
	trait Problem {
	type Node

	trait Result
	case object Rejected extends Result

	import slick.driver.H2Driver.api._

	import scala.concurrent.ExecutionContext.Implicits.global

	import scala.concurrent.Await
	import scala.concurrent.duration._

	object EnrichExample extends App {

	sealed case class Flag(val value: Boolean)

	// allows converting one class to another by providing missing fields
	object convert {

	@annotation.implicitNotFound("""
	You have not provided enough arguments to convert from ${In} to ${Out}.
	${Args}
	""")
	trait Convertible[Args, In, Out] {
	def apply(args: Args, in: In): Out
	}