Moving back to dev-platform. On 12/17/13 4:41 PM, Gregory Szorc wrote: > I guess what I'm trying to say is that SpiderMonkey/JavaScript appears > lacking in the "language services" arena.
The concrete features you mentioned are extracting doc comments and minimization, so that's what I'll address here. (What else did you have in mind? Tokenization, perhaps, for syntax highlighting? Anything else?) Doc comments can be done two ways: * In pure JS, using a Reflect.parse() implementation that provides comment syntax. This requires either supporting SpiderMonkey extensions in Esprima or supporting comment output in our parser. Neither sounds hard. * We could bless a particular notion of what a doc comment is and implement that in our parser, and surface the results via Reflect.parse. The former sounds better. It's more flexible. It's less code. And improving Esprima and/or our Reflect.parse implementation is valuable for tools other than documentation tools. > FWIW, this issue dovetails with us trying to minify chrome JS (bug > 903149). One can argue that if we had access to robust JavaScript > language services (possibly including minifying) from the engine > itself, we wouldn't be stuck in a rut there either. I interpret this as saying: We should have JS minimization, and architecturally it makes sense for that to be implemented in the JS engine. But I'm not sure I agree on either point. According to the latest in bug 903149, we're not sure minimization is worth pursuing. Architecturally, I think the argument is that minimization will be brittle in the face of new syntax, unless the JS engine hackers maintain it. OK. But I don't think this balances all the arguments against. There are already several good open-source minimizers for JS. We don't have the bandwidth to stand up and maintain a new minimizer nearly as good as (say) Google Closure Compiler. The reason existing minimizers don't work with Mozilla code is SpiderMonkey extensions; I think the long-term fix for that is to converge on ES6. (Short-term fixes are possible too.) Minimization comes in many flavors (consider bug 903149 comment 37) and I tend to think the JS engine should provide powerful general APIs that can be used to implement many kinds of minimization and many other things too. Reflect.parse is that kind of API. In bug 903149, I got to write a 7-line program with Reflect.parse that detected bugs in jsmin. You could write a primitive minimizer by starting with the code in Reflect_stringify.js, in <https://bug590755.bugzilla.mozilla.org/attachment.cgi?id=558508>, and just deleting the bits that output indentation and spacing. This is really cool! It's pure JS. Anyone who can hack JS could do it. That's the kind of API I want to support. -j _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
