Hacker News Reader

Comment by zamalek | Hacker News Reader

> Looks like Debian is mostly on top of it

I wonder... I'm assuming their concern surrounds stuff that is installed on-disk with the package manager. Is there any benefit at all to JS minification when the file:// protocol is in use? Marginal (if at all) improvements to parse time? Anything else? Or is "everyone doing it?"

View on HN

Apt can be used to install web applications to be hosted from a Debian based server, so just because you're installing a package on a machine doesn't mean the files it installs won't be accessed remotely.

V8 uses a function's length in characters, _including comments_, to make optimization decisions. By removing comments and shortening var identifiers internal to a function, I can imagine a number of functions dropping under that 600-char threshold. Would be great to measure.

Someone in the last thread mentioned that you can actually configure this limit. So it may be slightly more accurate in the ratio when minified but probably not worth it.

that seems like a terrible way to measure things. why not go by the number of some form of nodes after parsing? Parsing has to happen before optimization anyway.

Agreed, this is awful. Presumably it means that adding comments can slow your code down, which I would otherwise have thought a completely laughable suggestion.

The problem with JIT compiled languages is compilation time is as critical as the performance of the compiled code. Using string length happens to be quicker than producing ASTs. So while it is a dirty hack, it generally offers greater performance more often than not.

Nope. Parsing happens inline with execution, unless the function has less than 600 characters, where it'll be compiled down instantly. If it has any hotspots after that, they'll be JIT optimized.

It is a terrible way, but you can't complain that it's a lot faster than rewriting V8 to count nodes.

UglifyJS also evaluates constant expressions and that kind of thing. So you get a couple of basic optimizations.

A proper linter like JSLint or JSHint is preferable, but minifying is a basic syntax check. Obviously not the best way to do it, but it's a benefit.

Reply on news.ycombinator.com