Al Baker AlBaker

The introduction to Reactive Programming you've been missing

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.

Embedding an SSH-accessible REPL in a Clojure process

N.B. This is now a library, thanks to the efforts of the wonderful @mtnygard. And the README does a good job of making clear just how terrible an idea it is to actually do this. :)

As any Clojurist knows, the REPL is an incredibly handy development tool. It can also be useful as a tool for debugging running programs. Of course, this raises the question of how to limit access to the REPL to authorized parties. With the Apache SSHD library, you can embed an SSH server in any JVM process. It takes only a little code to hook this up to a REPL, and to limit access either by public key or

General Background and Overview

Probabilistic Data Structures for Web Analytics and Data Mining : A great overview of the space of probabilistic data structures and how they are used in approximation algorithm implementation.
Models and Issues in Data Stream Systems
Philippe Flajolet’s contribution to streaming algorithms : A presentation by Jérémie Lumbroso that visits some of the hostorical perspectives and how it all began with Flajolet
Approximate Frequency Counts over Data Streams by Gurmeet Singh Manku & Rajeev Motwani : One of the early papers on the subject.
[Methods for Finding Frequent Items in Data Streams](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.187.9800&rep=rep1&t

Here's an example of how to embed a Gist on GitHub Pages:

{% gist 5555251 %}

All you need to do is copy and paste the Gist's ID from the URL (here 5555251), and add it to a gist tag surrounded by {% and %}.

	@Grab( 'com.typesafe.akka:akka-actor_2.10:2.3.2' )
	@Grab( 'com.typesafe:config:1.2.0' )
	import groovy.transform.Immutable
	import akka.actor.ActorRef
	import akka.actor.ActorSystem
	import akka.actor.Props
	import akka.actor.UntypedActor
	import akka.actor.UntypedActorFactory
	import akka.routing.RoundRobinRouter
	import scala.concurrent.duration.Duration

	(ns clojure-conj-talk.core
	(:use [enchilada :only [canvas ctx canvas-size]]
	[monet.canvas :only [fill-style fill-rect]]
	[jayq.core :only [show]])
	(:require [cljs.core.async :refer [<! >! chan timeout]])
	(:require-macros [cljs.core.async.macros :as m :refer [go]]))

	(def colors
	(rand-nth [
	[

	(require '[clojure.core.async :refer [chan go >! <! >!! <!!]])
	(require '[clojure.core.async :as async])

	(defn chan-bridge
	([ch-source map-f ch-target]
	"map map-f onto ch-source and copy the result to ch-target"
	(chan-bridge (async/map map-f [ch-source]) ch-target))
	([ch-source ch-target]
	"in a loop read from ch-source and write to ch-target
	this function returns inmediately and returns the ch-target"

	import groovy.transform.*

	//////////////////////////////////////
	// Testing
	//////////////////////////////////////

	new MiniKanren().with {
	// for a given 'q' and 'r'
	def (q,r) = [ lvar( 'q' ), lvar( 'r' ) ]

	Latency Comparison Numbers (~2012)
	----------------------------------
	L1 cache reference 0.5 ns
	Branch mispredict 5 ns
	L2 cache reference 7 ns 14x L1 cache
	Mutex lock/unlock 25 ns
	Main memory reference 100 ns 20x L2 cache, 200x L1 cache
	Compress 1K bytes with Zippy 3,000 ns 3 us
	Send 1K bytes over 1 Gbps network 10,000 ns 10 us
	Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD

	alias usejava6='export JAVA_HOME=$(/usr/libexec/java_home -v 1.6) ; PATH=$JAVA_HOME/bin:$PATH'
	alias usejava7='export JAVA_HOME=$(/usr/libexec/java_home -v 1.7) ; PATH=$JAVA_HOME/bin:$PATH'
	alias usejava8='export JAVA_HOME=$(/usr/libexec/java_home -v 1.8) ; PATH=$JAVA_HOME/bin:$PATH'