acutmore

A compile-time 4-Bit Virtual Machine implemented in TypeScript's type system. Capable of running a sample 'FizzBuzz' program.

Syntax emits zero JavaScript.

type RESULT = VM<
  [
    ["push", N_1],         // 1
    ["push", False],       // 2
 ["peek", _], // 3

eyecatchup

Get/set ID3 meta tags using ffmpeg

A quick guide on how to read/write/modify ID3 metadata tags for audio / media files using ffmpeg.

FFmpeg has a free-form command line option that allows the user to specify key-value-pairs for encoding metadata. Let's take a look.

1. Read ID3 metadata

To list all global metadata tags for a media file, just set an input but no output file.

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

tsbarnes

[Scheme]
Name=Monokai (dark)
TabActivityColor=#a6a6e2e22e2e
ColorCursor=#f8f8f8f8f2f2
ColorForeground=#f8f8f8f8f2f2
ColorBackground=#272728282222
ColorPalette=#272728282222;#f9f926267272;#a6a6e2e22e2e;#f4f4bfbf7575;#6666d9d9efef;#aeae8181ffff;#a1a1efefe4e4;#f8f8f8f8f2f2;#757571715e5e;#f9f926267272;#a6a6e2e22e2e;#f4f4bfbf7575;#6666d9d9efef;#aeae8181ffff;#a1a1efefe4e4;#f9f9f8f8f5f5

jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
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 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

hallettj

// It is important to declare your variables.

(function() {
    var foo = 'Hello, world!';
    print(foo);  //=> Hello, world!
})();

// Because if you don't, the become global variables.

(function() {