It's a good glue language, like Python. Better than Python in the sense that its internal representation is based on tagged values instead of ubiquitous pointers: for example, 43243 represents itself and isn't a pointer to a some reference-counted PyObject representing an int.

And because Emacs Lisp a lisp, you get extensive syntactic malleability that you can use to build DSLs and convenience facilities.

Elisp is actually a very nice little language.

Your absence from emacs-devel is felt, there was so much excitement when you were around.

“Fast” is really a meaningless and vague word. What specific part of emacs lisp is faster than javascript in what regard?

For what it’s worth, V8 among with some other JITs are some of the fastest engines in the world: https://arewefastyet.com/#machine=29&view=breakdown&suite=as...

> V8 among with some other JITs are some of the fastest engines in the world

I find that doubtful, when the jvm is so close to native code in terms of performance, and mozilla said that wasm (or was it asm.js? Forget which) was still 50% slower theoretically than native code.

Hotspot among with other JVMs are no doubt fast -- but partially that came from Java being a static and compiled language.

Not saying that JavaScript is faster, but JavaScript is fast. If you look at the benchmarks I posted, you'll notice that 50% slower is hardly the norm -- many benchmarks have the VMs performing at a near-native performance, and the VMs are even faster in some cases.

In fact, number crunching in JavaScript has been fast for a long time, and even faster than Java in some cases: http://www.stefankrause.net/wp/?p=144

I'm not trying to advocate JavaScript's performance in anyway however. I'm merely pointing out the fact that performance cannot be single-handedly described as "fast" or "slow", especially "for sure". Context matters. A lot.

> still 50% slower theoretically than native code

How can something be theoretically slower? What's the difference between theoretically slower and practically slower?

Only practical implementations have a speed that you can talk about.

I don't know what you mean by 'theoretically' as an adverb there.

I suspect it means something like "according to calculations using a noticeably approximate model of reality". That's what people tend to mean, anyway. "Theoretically" is often code for "My model does not correspond to reality".

It annoys me, actually, that "theory" has this negative connotation of noncorrespondance.

Not being an emacs user, can you compile all that out to slim emacs down?

You can, but it's probably not worth the effort. Most of that's in the form of lazy-loaded byte code. Other than some lightweight stubs for the entry points, Emacs doesn't load those pieces until you use them.