ptaoussanis

(comment ; Fun with transducers, v2

  ;; Still haven't found a brief + approachable overview of Clojure 1.7's new
  ;; transducers in the particular way I would have preferred myself - so here goes:

  ;;;; Definitions
  ;; Looking at the `reduce` docstring, we can define a 'reducing-fn' as:
  (fn reducing-fn ([]) ([accumulation next-input])) -> new-accumulation
  ;; (The `[]` arity is actually optional; it's only used when calling
  ;; `reduce` w/o an init-accumulator).

francolaiuppa

// Requires https://www.npmjs.org/package/s3-policy and https://www.npmjs.org/package/node-uuid
var config = require('env/' + process.env.NODE_ENV),
  policy = require('s3-policy'),
  uuid = require('node-uuid');

// SETUP S3
const AWS_ACCESS_KEY = config.s3.accessKey;
const AWS_SECRET_KEY = config.s3.secret;
const S3_BUCKET = config.s3.bucket;

john2x

Clojure Destructuring Tutorial and Cheat Sheet

(Related blog post)

Simply put, destructuring in Clojure is a way extract values from a datastructure and bind them to symbols, without having to explicitly traverse the datstructure. It allows for elegant and concise Clojure code.

Vectors and Sequences

staltz

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.

---

swannodette

(ns om-data.core
  (:require [om.core :as om :include-macros true]
            [om.dom :as dom :include-macros true]
            [datascript :as d]))
 
(enable-console-print!)
 
(def schema {})
(def conn (d/create-conn schema))
 

arobson

Abstraction Suggestions

Summary: use good/established messaging patterns like Enterprise Integration Patterns. Don't make up your own. Don't expose transport implementation details to your application.

Broker

As much as possible, I prefer to hide Rabbit's implementation details from my application. In .Net we have a Broker abstraction that can communicate through a lot of different transports (rabbit just happens to be our preferred one). The broker allows us to expose a very simple API which is basically:

• publish
• request
• start/stop subscription

bowmanb

(ns my-project.http-server
  (:require [compojure.core :as compojure]
            [com.stuartsierra.component :as component]
            [my-project.my-resource :as my-resource]
            [ring.adapter.jetty :as jetty]))

(compojure/defroutes app
                     my-resource/handler)

(defrecord HTTPServer [port server]

seboudry

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns                     on recent CPU
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 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 4X memory

debasishg

General Background and Overview

1. 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.
2. Models and Issues in Data Stream Systems
3. 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
4. Approximate Frequency Counts over Data Streams by Gurmeet Singh Manku & Rajeev Motwani : One of the early papers on the subject.
5. [Methods for Finding Frequent Items in Data Streams](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.187.9800&rep=rep1&t

danielsz

(def history (Html5History.))
(.setUseFragment history false)
(.setPathPrefix history "")
(.setEnabled history true)

(let [navigation (listen history EventType/NAVIGATE)]
  (go 
     (while true
       (let [token (.-token (<! navigation))]
         (secretary/dispatch! token)))))