Rimu

Shuang Rimu

A blog about random stuff

Toggling Vim Latex-Suite's Macros

Image Attribution:

Bert Hymans. "Vim the editor that's also a ...". http://www.flickr.com/photos/heymans/8903973272/. Under a Creative Commons Attribution-NonCommercial-ShareAlike 2.0 License at http://creativecommons.org/licenses/by-nc-sa/2.0/deed.en (NOT CC-BY!).

June 8, 2013

latex, vim

The LaTeX-suite for Vim is a great tool for writing LaTeX code. Among its amazing features are its set of macros implemented with its IMAP() function. For example, typing EFI while in Insert mode will result in the following. 

\begin{equation}
	
	\label{<++>}
\end{equation}<++>

The <++> are little tags that Vim automatically jumps to and deletes (via Ctrl-j), allowing the user to write an equation in the equation environment and then immediately jump to writing a label and then immediately jump out of the equation environment without extraneous key movements. See here.

Unfortunately this can be a huge pain at times. I was trying to write the word “DELETE” in a LaTeX document and every time I would suddenly would be presented with “DEL–gigantic blob of table environment text here–.” It was rather annoying.

The LaTeX-suite comes with the Vim global variable “g:Imap_FreezeImap,” which if is “let”ed to 1, will disable these macros. I was looking to map these to a nice set of keys to allow for easy toggling back and forth.

Alas, it doesn’t seem that there’s a way of toggling variables (as opposed to Vim options) without using Vimscript functions. So I looked, with every intention of spending as little time and effort as possible, at a few tutorials of vimscript. As soon as I learned how to declare functions and negate variables, I figured I should be set.

So naturally I came up with 

function ToggleFreezeImap()
    let g:Imap_FreezeImap = !g:Imap_FreezeImap
endfunction

to add to my vimrc. Unfortunately this didn’t work. I spent some time puzzling over it. I changed into a conditional if-else statement. I looked up using global variables in conditional statements. Nothing seemed to click.

Apparently, what I was missing was that even global variables need to first be declared in my vimrc. So I needed something like 

let g:Imap_FreezeImap = 0
function ToggleFreezeImap()
    let g:Imap_FreezeImap = !g:Imap_FreezeImap
endfunction
noremap  :call ToggleFreezeImap()

.

So that concludes my first tentative, brief (VERY brief) foray into Vimscript.