[dherman]

All abstractions can make your code unreadable; the key, as always, is to create good abstractions and document them clearly. Macros are syntactic abstractions. It's just as important to document them as it is for functions or objects. Of course, if you just have a little local macro that you're using for convenience, looking at the implementation may be sufficient. But when you write a macro that you want to share from a module, rather than requiring your clients to read the implementation, you document the syntax and the semantics, just like you would if you were writing a separate language.

But by having macros directly in JS, instead of having to use a whole language that compiles to JS, you can combine syntactic features from different sources. For example, right now there's no way to use one feature you like from CoffeeScript with another feature you like from TypeScript. You just can't combine them. But with macros, you could import two different syntaxes from two different libraries and use them in the same code.

On top of that, if we actually had macros in a future version of the standard, you wouldn't even have to precompile the macros offline, and you wouldn't need a preprocessing step at all. (For latency purposes, you might want to preprocess macros offline as an optimization. But for development, not having to do a preprocessing step is more convenient.)

Dave

[saebekassebil]

So this is all in the holy name of making JavaScript the assembly language of the web? Making it possible for every JavaScripter to write "his own" JavaScript syntax definitions meaning that I'll (as a contributor or just casual watcher) would have to read his whole collection of macros before I could begin to understand the code?

I don't think this can be compared to API's as they still follow the regular syntactic definitions - This will be like reading a completely new language every time I read a different repository. (Of course this is a worst-case scenario as I imagine that many macros will be used across several projects, but still.)

Is all hope gone for writing vanilla JS gone? And isn't macros kinda going in the opposite direction than the ES specs? There's no use for many of the ES6/7 features as they could just be mocked up in macros.