Which use cases are slow for you ? you used it on large code base or parsed cpp source ?
A quicker emacs would be neat, but most of the time emacs gets speed from flexibility (it might be slow but I can automate something) and design decision (magit for instance blows 99% of the fastest git interfaces)
ps: one part that realize is that I don't like emacs daemon, and even curated my setup on windows (probably the culprit) takes a few seconds. It's not slow but often I want a buffer right away so I use notepad u_u; stupid I know.
Also worth mentioning that whatever is slow, profile it to find out why. Sometimes only the smallest tweak is necessary to get it up to speed again. (Different tweaks for different configurations, so can't be a default.)
For interactive use, profiling is as simple as M-x profiler-start, doing what causes the slowdown, and then M-x profiler-report.
I would happily agree but I lost the one emacs and 119422 buffers mindset. I get lost in my own shit. I should spend time improving my ibuffer grouping but even then.. I like the idea of pop, edit, kill (which causes my harm).
My solution: Accept that there will be dozens or even hundreds of buffers and use helm-for-files (which lists recent buffers first) to switch between the buffers I care about at any given time. Works really well.
I've noticed that pasting large amounts of text (> 1000 lines) can make it grind to a halt for several minutes. I don't know if it's due to the mode I'm in.
More than the number of lines, it's the number of characters on a single line that causes the slowdown. Thankfully I don't have a real usage scenario where I handle thousand character line files.
I can edit multi-thousand line (5k+) Org documents just fine. So it's probably the major mode or some minor mode(s), or a combination.
In my experience that's often due to major modes that try to format and syntax-highlight on the fly. Keep in mind that some forms of pasting are really equivalent (from Emacs' PoV) to a crapton of keystrokes being entered.
Anyway, the workaround I have for the occasional time I have huge things to paste is to switch the buffer to fundamental-mode before pasting, and then switching back.
As a curiosity, what kind of things are you pasting that are that big?
Long lines are slow, but it handles well otherwise. For long lines, I disabled bidi-display-reordering and switched to fundamental-mode and it really helps.
1k lines does not stress many editors. It only stresses emacs when the major mode is doing lots of stuff to highlight and format.
I regularly used other editors on C files with 30k+ lines, 15 years ago when machines were slower.
Emacs' real weakness is an over-reliance on regexes for highlighting and poor integration with sources of semantic and symbolic information for richer highlighting, editing and browsing. That, and synchronous operations for the same.
Honestly, I don't much notice emacs being slow, esp. given how much it's doing for me under the hood.
One key thing is to always always always use emacs in dæmon mode, rather than starting up a new emacs for each file (as would be done with vi). With an always-running emacs instance, start-up time is no longer a factor, and the editor itself is plenty fast enough once it's running.
ELISP is a pretty fast language, faster than VimScript or JS for sure.
EDIT: Also, Emacs is bloated is bloated because it's not just a editor its's an Web Browser, Email Client, News Reader, Music Player and File Manager. If people want a light emacs, they can go use uEmacs or become the last JEDi.
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.
> 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.
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.
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.