FWIW: I (@rondy) am not the creator of the content shared here, which is an excerpt from Edmond Lau's book. I simply copied and pasted it from another location and saved it as a personal note, before it gained popularity on news.ycombinator.com. Unfortunately, I cannot recall the exact origin of the original source, nor was I able to find the author's name, so I am can't provide the appropriate credits.
Re: http://blog.chromium.org/2015/03/new-javascript-techniques-for-rapid.html
As mentioned in our Chromium blog post, Chrome 41 introduces support for streaming parsing of JavaScript files using the async or defer attributes. This is where the V8 parser will parse any incoming JavaScript piece-by-piece so the compiler can immediately begin compiling the AST when script loading has completed. This lets us do something useful while waiting for the page to load. Compare:
This means parsing can be removed from the critical path when loading up the page. In these cases such scripts are parsed on a separate thread as soon as the download begins, allowing parsing to complete very soon after the download has completed (milliseconds), leading to pages (potentially) loading much faster.
go to https://github.com/maxogden/art-of-node#art-of-node to view the newer versions of this document
