Arun Udayashankar uarun

Babun Tab Completion

If babun tab completion stops working, then do the following:

$ cd
$ compinit
$ cp .zcompdump .zcompdump-$HOSTNAME-$ZSH_VERSION

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

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

Useful Scalac Options

-encoding "UTF-8"

-target:jvm-1.6

Uses the ASM Compiler backend to generate bytecode (Scala 2.10)

-deprecation

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

	module Algebra where

	import Prelude
	import Control.Monad.Eff (Eff)
	import Data.Maybe (Maybe(..))


	newtype ConsoleAlg f = ConsoleAlg
	{ printLn :: String -> f Unit
	, readLn :: f String


	import org.apache.avro.io.DatumReader
	import org.apache.avro.io.DecoderFactory
	import org.apache.avro.specific.SpecificDatumReader
	import org.apache.flink.api.common.typeinfo.TypeInformation
	import org.apache.flink.api.java.typeutils.TypeExtractor

	class AvroDeserializationSchema[T <: SpecificRecordBase: ClassTag](private val baselineMessage: () ⇒ T) extends DeserializationSchema[T] {

	override def deserialize(message: Array[Byte]): T = {

	import scalaz.\/
	import scalaz.syntax.either._

	object Example2 {
	// This example simulates error handling for a simple three tier web application
	//
	// The tiers are:
	// - the HTTP service
	// - a user authentication layer
	// - a database layer

	// Please comment in case of typos or bugs

	import scala.slick.driver.H2Driver._
	val db = Database.for...(...)

	case class Record( ... )
	class Records(tag: Tag) extends Table[Record](tag,"RECORDS"){
	...
	def * = ... <> (Record.tupled,Record.unapply)
	// place additional methods here which return values of type Column

	13:15 <xQuasar> \| HASKELL IS FOR FUCKIN FAGGOTS. YOU'RE ALL A BUNCH OF
	\| FUCKIN PUSSIES
	13:15 <xQuasar> \| JAVASCRIPT FOR LIFE FAGS
	13:16 <luite> \| hello
	13:16 <ChongLi> \| somebody has a mental illness!
	13:16 <merijn> \| Wow...I suddenly see the error of my ways and feel
	\| compelled to write Node.js!
	13:16 <genisage> \| hi
	13:16 <luite> \| you might be pleased to learn that you can compile
	\| haskell to javascript now