Question

Does anyone know how to have vim convert the html entities of math symbols into the math characters?

For example:

≠ becomes ≠

∴ becomes ∴

here is a table with the symbol html entities http://barzilai.org/math_sym.htm

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Updated: Solved, bignose came through with the solution.

using the :digraphs functionality of Vim. with a character encoding of Unicode,

see ‘:help digraphs’ for documentation

I’m Still looking for a monospace Unicode font so it renders completely but with extra spaces it works great.

In order to see math characters UTF-8 has to be the encoding and a font that will display those characters.

I added the following to my vim configuration files.

created custom file: mathdoc.vim in syntax/

' set the encoding to be utf-8, requires gVim or a terminal capable of ' unicode see ':help Unicode' for details set encoding=utf-8 ' requires a font that has characters for the higher uniocode symbols set guifont=MS\ Gothic 

I added this to filetype to set this for my own custom extension .txtmt

au BufNewFile,BufRead *.txtmt   setf mathdoc 

but you could alternately call this with the file open:

:set ft=mathdoc 

digraphs works great as bignose specified below here is how it works

in insert mode: press control+k followed by:

∴ is S*

≠ is !=

∑ is +Z

≡ is =3

⇐ is <=

⇒ is =>

⇔ is ==

∀ is FA

∃ is TE

∋ is -)

see :digraphs for the complete list * note if you only see half a screens worth you’re character encoding is not unicode, unicode characters cover several screens, type :set encoding=utf-8 to switch to utf-8.

The table in the above link has the numbers for the characters that you’ll need to find the keyboard shortcuts, 8756 is ∴ for example

Answer 1

You want what Vim calls “digraphs”: read :help digraphs to see how they’re used, and :digraphs to list the defined ones in your Vim.

Summary: in insert mode, press Ctrl+K (which causes Vim to display a highlighted ?, waiting for further input), then the defined two characters of the digraph. Vim then replaces what you typed with the defined resulting character. E.g. Ctrl+K, !, = produces ‘≠’.