emilio

var USELESS_PROPERTIES = [];

function processContainer(container) {
  if (container instanceof CSSSupportsRule)
    if (!CSS.supports(container.conditionText))
      return false;
  if (container instanceof CSSMediaRule)
    if (!matchMedia(container.conditionText).matches)
      return false;
  if (container.media && container.media.mediaText)

getify

Parens And Performance

Years ago, some smart folks that worked on JS engines realized that not all JS that's loaded into a page/app initially is needed right away. They implemented JIT to optimize this situation.

JIT means Just-In-Time, which means essentially that the engine can defer processing (parsing, compiling) certain parts of a JS program until a later time, for example when the function in question is actually needed. This deferral means the engine is freer to spend the important cycles right now on the code that's going to run right now. This is a really good thing for JS performance.

Some time later, some JS engine devs realized that they needed to get some hints from the code as to which functions would run right away, and which ones wouldn't. In technical speak, these hints are called heuristics.

So they realized that one very common pattern for knowing that a function was going to run right away is if the first character before the function keyword was a (, because that usually m

muan

Update: See https://github.com/muan/details-on-details instead.

---

I did a talk at Brooklyn JS called Details on <details> on 2018/07/19. I have way more details prepared than the ones that fit in the slides, so here's the real details on <details>. ❤️

– @muan

Spec

megamaddu

PureScript

What is it?

• Compiles to JavaScript
• Haskell-inspired type system (with some improvements!)
• No runtime (unlike Elm, GHCJS, etc)
• A focus on readable and debuggable JavaScript

amir20

#!/usr/bin/ruby

if ARGV.size.zero?
  puts %Q[
    Usage:
      ./to_csv.rb file.yml > out.csv
  ]
  exit
end

spoike

var EventEmitter = require('events').EventEmitter,
    _ = require('lodash');

/**
 * Creates an action functor object
 */
exports.createAction = function() {

    var action = new EventEmitter(),
        eventLabel = "action",

scmu

{-

A program searching for solutions of a board puzzle
given by a friend.

The aim is to fill in a 8 by 8 square using the
given 8 pieces. Each piece has a particular shape and
can be rotated and flipped.

I am not satisfied with this program yet. The program

nolanlawson

Pinafore browser bugs

Chrome

• sticky element hit detection fails occasionally (nolanlawson/pinafore#1)
• video fullscreen in modal on Android forces landscape resize on entire document (no repro in iOS Safari, Firefox Android)
• modal with transform is blurry (nolanlawson/pinafore#71)

Edge

developit

An Alias to run Chrome with tracing enabled

For Chrome Canary:

alias hydra='/Applications/Google\ Chrome\ Canary.app/Contents/MacOS/Google\ Chrome\ Canary --no-sandbox --js-flags="--user-data-dir=/tmp/profile --trace-hydrogen --trace-phase=Z --trace-deopt --code-comments --hydrogen-track-positions --redirect-code-traces"'

For regular ol' Chrome:

rayshih

你可能其實不懂繼承 - 什麼是 Covariance 跟 Contravariance

在近代高等程式語言快（ㄏㄨˋ）速（ㄒ一ㄤ）演（ㄔㄠ）化（ㄒㄧˊ）的狀況下，很多 strong type 的程式語言都開始有了 generic 的設計， 舉例來說：

（這只是大略分類）

• Mobile: Swift, Kotlin
• Frontend: Flowtype, TypeScript
• 後端語言：Python (pyre), Scala, C#, Java （沒錯！現在連 Java 都有）