How to enter commands starting with i

Question

vimtex lists some commands like ie to be entered in mode nxo. How do I do that? What is mode nxo? (Usually i brings me into insert mode, and e then just inserts an e.)

Answer 1

In vimtex, the mappings like ie are actually vim text objects (not sure about the right vim nomenclature though). They work together with vim operators like d (delete).

In particular ie stands for any tex environment like equation, itemize, .... For example, if you cursor is somewhere inside

\begin{equation}
    Ax = b
\end{equation}

the command die will delete everything between \begin{equation} and \end{equation} and leave you with

\begin{equation}\end{equation}

.

Answer 2

N represents Normal mode and O represents operational mode and X represents Ex mode. Mappings can be done in normal, ex (similar to command line), visual, insert and operational mode as well. To know more, http://vimdoc.sourceforge.net/htmldoc/intro.html

Vim knows to distinguish key mappings and predefined commands. For example, if you have a mapping like ie in normal mode, when you press i, it waits for some time (timeout) and checks whether you entered e so that it can execute the mapping. If you didn't press any key within that time, it goes to insert mode.

So, whatever mapping you have, you have to press the characters in mapping one after the other immediately (within the timeout time). If you do so, that mapping get executed. If you fail to complete the mapping (fail to press all keys within time), the predefined command with the first key or (first+second key) gets executed.

One example: Let's take di{. This mapping deletes text inside a { and } pair. Suppose if you press d , it waits for some keys to be pressed. This waiting mode is called operational mode. If you didn't press i{ within that time, the command is incomplete and gets cancelled.