removing spell syntax highlighting in vim

Question

This question is a sequel question of this one. I have the following script that removes capitalized words from vim spell check.

syn match myExCapitalWords +\<\w*[A-Z]\K*\>+ contains=@NoSpell

But it works only if I do syn clear first. But then all other highlighting (e.g. markdown) gets lost. I went through syn list to see what might be causing the conflict, but now I am out of clue.

Answer 1

It looks like you're extending arbitrary syntaxes with your myExCapitalWords group. Whether / in which syntax items that works depends on the underlying syntax. Unfortunately, it is not possible to extend arbitrary syntaxes in a blanket way. That's why you're seeing problems that can only be solved via :syn clear (which gets rid of the underlying syntax).

A syntax contains multiple groups, some of which are usually contained= in others. If you introduce a new syntax, it will only apply to where no other syntax group already matches. You can force your group into others via containedin=TOP or even containedin=ALL, but that overlay may prevent other original groups from matching, and causes strange effects because their own contains= or nextgroup= now don't apply.

So, unfortunately, there's no general solution for this. If you're only interested in a few syntaxes, you can tweak your one-liner to make it cooperate with the underlying syntax (e.g. try containedin={syntaxName}Comment{s}), but there's no generally applicable solution.