The Art of WebAssembly

(pg. 15)

IIFE : Immediately Invoked Function Expression

I never knew that's what this pattern was called

(async () => {})();

^^ tc39/proposal-do-expressions#34 ^^ proposal for a "do while" type syntax for IIFEs

Chapter Notes

Introduction

Java is a propireitary language and requires plugins to work with the browser. "... and the plugin technology eventually fell out of fasion when it became a security and malware nightmare." (pg. xxi)

I wonder what this is referencing specifically, was it just there were no popular browsers that could handle java coming from a web server?

Chapter 1 - An Introduction to WebAsssembly

"WebAssembly is a virtual Instruction SSet Architeccture (ISA) for a stack machine." (pg. 13)


"According to the Mozilla Foundation, WebAsssembly code runs between 10 percent and 800 percent faster than the equivalent JavaScript code." (pg.13)

Author is on Nodejs version 12.14.0 (pg. 13)

Chapter 2 - WAT text basics

globals.wat

import_i32: 5_000_000_000, // _ is ignored in numbers in JS and WAT

^^ neat note about underscore in js. I guess this makes sense since comma is an operator in JS (and C, and perl, not java though in java its a separator and doesn't evaluate to anything)

Chapter 3 - Functions and Tables

illegal_pop.wat

this is kind of unexpected scope behavior, this will throw an error when you attempt to compile.
Functions can't access variables that exist on the stack unless params are declared/expected

wat2wasm illegal_pop.wat

func_perform.js

why'd he do this inside paren?

// destructure wasm_call and js_call from obj.instance.exports
    ({ wasm_call, js_call } = obj.instance.exports);

Chapter 4 - Low-Level Bit Manipulation

"floating-point numbers have a dedicated sign bit and therefore don't use 2s complement." (pg. 72)

Chapter 7 - Web Applications

Is connect an express.js product?

These middleware and libraries are officially supported by the Connect/Express team:

(pg.144 add_message.html)

is there a reason for not declaring add_message_function before assigning? I think this would be hoisted but seems strange to do that on purpose.

Chapter 8 - Working with the Canvas

"The canvas element was introduced in 2004 by Apple for itts Safari web browser and adopted as a part of the HTML standard in 2006"

^^ This is shockingly recent for some reason

Games like Atari's _Asteroids_ or Namco's _Pac-Man_ didn't need any extra code to have this effect; instead, their screens were 256 pixels wide and used an 8-bit number to store the x-cordinate. So if a game object had an x-coordinate of 255 and moved one pixel to the right, the single byte value would roll back over to 0, and the game object would reappear on the left side of the screen. (pg.176)

^^ CLEVER! Overflow implementing a feature

Chapter 11 - AssemblyScript

"We then call loader.demangle, passing it the module returned by loader.instantiate. The demangle function returns an object structure that provides us with functions we can use..." (262)

not seeing this demangle method called anywhere, according to assemblyscript.org its not usually required.
it does get called later when we exted Vector2D in vector_loader.ts and destructure the two exports in vector_loader.js, just not in the first version of the module.
we can kind of guess, but was there an explanation for this anywhere?
```
    env: {
        abort: () => {}
    }
```

mbmcmullen27/artofwasm