gaearon

function mapValues(obj, fn) {
  return Object.keys(obj).reduce((result, key) => {
    result[key] = fn(obj[key], key);
    return result;
  }, {});
}

function pick(obj, fn) {
  return Object.keys(obj).reduce((result, key) => {
    if (fn(obj[key])) {

mohanmca

// load error messages from a log into memory
// then interactively search for various patterns

// base RDD
val lines = sc.textFile("log.txt")

// transformed RDDs
val errors = lines.filter(_.startsWith("ERROR"))
val messages = errors.map(_.split("\t")).map(r => r(1))
messages.cache()

mohanmca

$ ./bin/spark-shell
14/04/18 15:23:49 INFO spark.HttpServer: Starting HTTP Server
14/04/18 15:23:49 INFO server.Server: jetty-7.x.y-SNAPSHOT
14/04/18 15:23:49 INFO server.AbstractConnector: Started SocketConnector@0.0.0.0:49861
Welcome to
      ____              __
     / __/__  ___ _____/ /__
    _\ \/ _ \/ _ `/ __/  '_/
   /___/ .__/\_,_/_/ /_/\_\   version 0.9.1
      /_/

nolanlawson

// Promise.all is good for executing many promises at once
Promise.all([
  promise1,
  promise2
]);

// Promise.resolve is good for wrapping synchronous code
Promise.resolve().then(function () {
  if (somethingIsNotRight()) {
    throw new Error("I will be rejected asynchronously!");

retronym

indylambda: Putting invokedynamic to work for Scala

Java 8 introduced lambdas to the Java language. While the design choices differ in many regards from Scala's functions, the underlying mechanics used to represent Java lambdas is flexible enough to be used as a target for the Scala compiler.

Lambdas in Java

Java does not have canonical heirarchy of generic function types (ala scala.FunctionN), but instead allows a lambda to be used as a shorthand for an anonymous implementation of an Functional Interface

Here's an example of creating a predicate that closes over one value:

bendc

// array utils
// =================================================================================================

const combine = (...arrays) => [].concat(...arrays);

const compact = arr => arr.filter(Boolean);

const contains = (() => Array.prototype.includes
  ? (arr, value) => arr.includes(value)
  : (arr, value) => arr.some(el => el === value)

johnynek

/**
 * To get started:
 * git clone https://github.com/twitter/algebird
 * cd algebird
 * ./sbt algebird-core/console
 */

/**
 * Let's get some data. Here is Alice in Wonderland, line by line
 */

prakhar1989

Rich Hickey on becoming a better developer

Rich Hickey • 3 years ago

Sorry, I have to disagree with the entire premise here.

A wide variety of experiences might lead to well-roundedness, but not to greatness, nor even goodness. By constantly switching from one thing to another you are always reaching above your comfort zone, yes, but doing so by resetting your skill and knowledge level to zero.

Mastery comes from a combination of at least several of the following:

wozmir

##Scala eXchange 2014 slides

collected by Adam Warski

Feel free to complete the list!

The Binary Compatibility Challenge by Martin Odersky

A Skeptic's Look at scalaz' "Gateway Drugs”: A Practical Exploration by Brendand McAdams

gangstead

Friday 11/14/14

notes by Steven Gangstead

Rapture Art of One-liner - Jon Pretty @propensive

rapture.io -collection of libraries for scala

jawn json parser. Quicker than Jackson, and I guess Jackson must normally be considered the quickest.

My thoughts: Awesome talk. Look into rapture, looks useful. Jon is smart.