Could someone explain “rolling one's finger” when used in a Vim context?

Question

From a recent reddit post I saw: https://old.reddit.com/r/vim/comments/bm0ihb/evolution_of_a_vim_user/emt4p4a/

I keep seeing jk, am I the only one who does kj? It feels more natural to roll from the outside in than from the inside out. Is there a reason jk is more popular?

I also saw it in this answer: https://vi.stackexchange.com/a/18081/25025

For me it's more natural to roll from pinky to index finger. Therefore I chose to use kj. Also, I did a grep -rHin kj ~/src (recursive grep on the parent directory of all my source code) and found no matches.

and also this great book: http://learnvimscriptthehardway.stevelosh.com/chapters/10.html

It's typed with two separate keys, so you can "roll" your fingers instead of using the same one twice.

But I don't really know what this physically means. Could someone explain as it seems very ubiquitous in the Vim community.

Answer 1

In the context given, it just means to press one key with one finger, and then immediately press an adjacent key with an adjacent finger. While doing so, your entire hand may rotate slightly. Hence: “roll”.

For what it’s worth, whilst I may have read other people use the word in this way before, I haven’t noticed that they did so, and certainly wouldn’t have described it as a “roll” myself, so I’m not sure if the term as ubiquitous in the community as you think it is.

Answer 2

Finger rolling describes typing keys such that successive keys are typed moving towards the center of the keyboard (inward rolling) or edges of the keyboard (outward rolling). Said another way, going from your pinky to your index finger, or the reverse. It's like drumming your fingers (see picture). On a Qwerty keyboard "asdf" and "awe" are examples of inward rolling, and "jkl;" and "few" of outward rolling. As it involves multiple fingers you wouldn't say "rolling one's finger" but "rolling one's fingers".

The term "finger rolling" is very common in keyboard layout communities. Particularly those focused on functional layouts. That is, choosing where each letter or symbol is located on the keyboard. Qwerty, Dvorak, and Colemak are examples of different functional layouts. Finger rolling is considered to be a quick and comfortable motion for typing. Many layouts prioritize common letter sequences, like t-h-e, so that they can be typed with a finger roll.

I don't think the term is ubiquitous in the Vim community. But there is a lot of overlap between the keyboard layout and Vim community as both are concerned with efficient keyboarding. It is really just a typing term, and appropriate to discussing whether "jk" or "kj" is a more natural, comfortable, or quick to type remap for escape.