How to use TexMathZones in Markdown Syntax, for Snippets?

Question

I am a recent and very happy Vim User. I write Mathematics and Computer Science Lecture Notes in Markdown Files, organized in a Vimwiki. I use the UltiSnips Snippet Plugin.

This plugin provides me with the possibility of defining snippets which only expand in a TexMathZone ("UltiSnips-context-snippets"). This happens through a Python function (see [1] below) returning true if the cursor is in a TexMathZone. That means that snippet expands when within $ or $$ delimiters (TexMathZoneX, TexMathZoneY).

This works perfectly in .tex Files, but not in .md Files. Setting the syntax to Tex by :set syntax=tex makes it work, but breaks markdown preview and syntax highlighting, which is unwanted.

I suspect this is because the syntax file for the markdown filetype does not define TexMathZone

How can I define or extend a markdown syntax file, such that the function in [1] delivers the same behaviour in markdown files as in Tex files? It should not inherit the other Tex syntax, and it should keep markdown syntax.

References:
[1] Minimal markdown.snippets file, as seen on Gilles Castel's Snippet Configuration File :

global !p
texMathZones = ['texMathZone' + x for x in ['A', 'AS', 'B', 'BS', 'C', 'CS', 'D', 'DS', 'E', 'ES', 'F', 'FS', 'G', 'GS', 'H', 'HS', 'I', 'IS', 'J', 'JS', 'K', 'KS', 'L', 'LS', 'DS', 'V', 'W', 'X', 'Y', 'Z', 'AmsA', 'AmsB', 'AmsC', 'AmsD', 'AmsE', 'AmsF', 'AmsG', 'AmsAS', 'AmsBS', 'AmsCS', 'AmsDS', 'AmsES', 'AmsFS', 'AmsGS' ]]
texIgnoreMathZones = ['texMathText']
texMathZoneIds = vim.eval('map('+str(texMathZones)+", 'hlID(v:val)')")
texIgnoreMathZoneIds = vim.eval('map('+str(texIgnoreMathZones)+", 'hlID(v:val)')")
ignore = texIgnoreMathZoneIds[0]
def math():
    synstackids = vim.eval("synstack(line('.'), col('.') - (col('.')>=2 ? 1 : 0))")
    try:
        first = next(i for i in reversed(synstackids) if i in texIgnoreMathZoneIds or i in texMathZoneIds)
        return first != ignore
    except StopIteration:
        return False
endglobal

context "math()"
snippet t "test" iAe
test!
endsnippet

Answer 1

This works for markdown files with the vimwiki filetype. The only change needed is the addition ["VimwikiMath", "VimwikiEqIn"] to texMathZones.

texMathZones = ['texMathZone' + x for x in ['A', 'AS', 'B', 'BS', 'C', 'CS',
'D', 'DS', 'E', 'ES', 'F', 'FS', 'G', 'GS', 'H', 'HS', 'I', 'IS', 'J', 'JS',
'K', 'KS', 'L', 'LS', 'DS', 'V', 'W', 'X', 'Y', 'Z', 'AmsA', 'AmsB', 'AmsC',
'AmsD', 'AmsE', 'AmsF', 'AmsG', 'AmsAS', 'AmsBS', 'AmsCS', 'AmsDS', 'AmsES',
'AmsFS', 'AmsGS' ]] + ["VimwikiMath", "VimwikiEqIn"]

I found those by inspecting a file with this vimscript. It prints all the syntax tags at the cursor location.

for id in synstack(line('.'), line('.'))
   echo synIDattr(id, "name")
endfor

Note that text in equation mode escapes the math context. ($$\text{Lorem} $$)