tonyg

#lang racket/base
;; Monads in Racket, including polymorphic bind, return and fail.
;; Haskell-like do-notation.

(provide define-monad-class
         (struct-out monad-class)
         monad?
         gen:monad
         monad->monad-class
         determine-monad

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)

oakes

Contents

• Why care about Rust?
• The Toolchain
• Creating a New Project
• Modules
• Crates
• Types
• References
• Mutability

mark-adams

using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;

namespace aes_example
{
    using System;

davidfowl

$/
  artifacts/
  build/
  docs/
  lib/
  packages/
  samples/
  src/
 tests/

tsiege

ANNOUNCEMENT

I have moved this over to the Tech Interview Cheat Sheet Repo and has been expanded and even has code challenges you can run and practice against!






\

stuart11n

git branch -m old_branch new_branch         # Rename branch locally    
git push origin :old_branch                 # Delete the old branch    
git push --set-upstream origin new_branch   # Push the new branch, set local branch to track the new remote

twokul

Hidden classes in JavaScript and Inline Caching

Knowing how internals work is always a good. Pretty much for everything. Cars, trains, computers, you name it. It gives you an insight on what happens under the hood. You also act/react differently based on this knowledge.

As you might have guessed, it’s also true for web development. Knowledge of CSS transitions allows you to achieve better performance and not to use JavaScript in most cases. Knowledge of V8 internals allows you to write more performant JavaScript code. So let’s talk about V8 a little.

A little about V8

V8 is a JavaScript engine built by Google. Firefox built SpiderMonkey, Opera built Carakan and Microsoft built Chakra. One very important difference between V8 and other JavaScript engines is that V8 doesn’t generate any intermediate code. It compiles JavaScr

emad-elsaid

require 'open-uri'
require 'json'

language = 'en'

print 'What do you need to know? : '
article = URI::encode gets.chomp

request_url = "http://#{language}.wikipedia.org/w/api.php?action=parse&page=#{article}&format=json&prop=text&section=0"

chanks

Turning PostgreSQL into a queue serving 10,000 jobs per second

RDBMS-based job queues have been criticized recently for being unable to handle heavy loads. And they deserve it, to some extent, because the queries used to safely lock a job have been pretty hairy. SELECT FOR UPDATE followed by an UPDATE works fine at first, but then you add more workers, and each is trying to SELECT FOR UPDATE the same row (and maybe throwing NOWAIT in there, then catching the errors and retrying), and things slow down.

On top of that, they have to actually update the row to mark it as locked, so the rest of your workers are sitting there waiting while one of them propagates its lock to disk (and the disks of however many servers you're replicating to). QueueClassic got some mileage out of the novel idea of randomly picking a row near the front of the queue to lock, but I can't still seem to get more than an an extra few hundred jobs per second out of it under heavy load.

So, many developers have started going straight t