Hacker News Reader

I'd like to learn enough to understand the statement "JSX is just a JS primary," and I can't find out what a "$lang primary" is in PLT. Can you point out some resources for me to figure this out?

View on HN

The full name is primary expression. The meat of it is that a primary is usually just a literal value, identifier, or something in parentheses, but it varies based on the particular language.

For a deep dive you'll want to read resources about parsing. To name one article that came up recently on HN, take a look at "Why Parsing Tools are Hard" [0].

[0]: http://blog.reverberate.org/2013/09/ll-and-lr-in-context-why...

The previous comment is trying to sound smart by using obscure terminology. I would guess they mean to say that JSX is a translated subset of JS?

Thanks for your generosity. This is what I was referring to: JSX extends the PrimaryExpression in the ECMAScript 6th Edition (ECMA-262) grammar.

Please take a look at the draft JSX spec [0] for details.

[0]: https://github.com/facebook/jsx

Reply on news.ycombinator.com