Jannis

;; Run using a local build of ClojureScript master, e.g.:
;; clj -Sdeps '{:deps {org.clojure/clojurescript {:mvn/version "1.10.155"}}}' -i build.clj

(require '[cljs.build.api :as b])

(b/watch "src"
  {:output-dir "out"
   :output-to "out/main.js"
   :optimizations :none
   :verbose true

aphyr

Hi S-------. I'm not an expert in performance benchmarking--I focus on 
correctness and safety--but I have a few pieces of advice here.

0. Pick multiple workloads that cover the gamut of behaviors in each DB.  
*Don't* choose a completely sharded workload for VoltDB. Don't choose a 
purely commutative workload for Cassandra. Cassandra's Paxos 
implementation is slow and a good benchmark will demonstrate 
that--however, it *doesn't* (I think?) require a global coordinator, 
which means it might *scale* better than a single-coordinator system 
like, say, VoltDB. Talk about those differences!

swannodette

Externs Inference

Integrating third party JavaScript libraries not written with Google Closure Compiler in mind continues to both be a source of error for users when going to production, and significant vigilance and effort for the the broader community (CLJSJS libraries must provide up-to-date and accurate externs).

In truth writing externs is far simpler than most users imagine. You only need externs for the parts of the library you actually intend to use from ClojureScript. However this isn't so easy to determine from Closure's own documentation. Still in the process of writing your code it's easy to miss a case. In production you will see the much dreaded error that some mangled name does not exist. Fortunately it's possible to enable some compiler flags :pretty-print true :pseudo-names true to generate an advanced build with human readable names. However debugging missing externs means compiling your production build for each missed case. So much time wasted for such simple mistakes damages our sen

garybernhardt

This document has moved!

It's now here, in The Programmer's Compendium. The content is the same as before, but being part of the compendium means that it's actively maintained.

paulirish

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

• elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

oakes

Contents

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

addyosmani

CSS Layout Debugger

A tweet-sized debugger for visualizing your CSS layouts. Outlines every DOM element on your page a random (valid) CSS hex color.

One-line version to paste in your DevTools

Use $$ if your browser aliases it:

~ 108 byte version

ryanflorence

var Dialog = React.createClass({
  render: function() {
    // 1) render nothing, this way the DOM diff will never try to do
    //    anything to it again, and we get a node to mess with
    return React.DOM.div();
  },

  componentDidMount: function() {
    // 2) do DOM lib stuff
    this.node = this.getDOMNode();

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.

---

jonleighton