Vim does not take umlauts as word characters

Question

When I write a German text containing something like abücd for instance and to a dw in front, it will only delete the ab since it does not interpret ü as a word character.

When I edit reStructuredText, I have

iskeyword=38,42,43,45,47-58,60-62,64-90,97-122,_

That explains why the umlauts are not marked, but I do not understand where this comes from. When I just open gVim this is set to

iskeyword=@,48-57,_,192-255

Where could this be coming from?

Answer 1

The @ character in iskeyword includes all characters for which isalpha() (C function) is TRUE; in modern (last 20 years) libc implementations this also looks for unicode characters.

Your second iskeyword uses 97-122 (a-z) and 64-90 (A-Z), which doesn't include all the variants with the various diacritics (such as the umlaut/diaeresis/trema).

So the solution is to replace 97-122 and 64-90 with @.

This funky iskeyword comes from the LISP syntax file; the rst syntax file includes a bunch of other syntax files for highlighting the code blocks.

Luckily you can set which languages to include with the g:rst_syntax_code_list variable. The default is:

let g:rst_syntax_code_list = ['vim', 'java', 'cpp', 'lisp', 'php', 'python', 'perl']

Since it's unlikely that you need LISP syntax highlighting in your reStructuredText file, you can probably just remove it. Just add it anywhere in your vimrc file, if it's defined, the syntax file will use that value instead of defining its own.

In my opinion, you probably want to use:

let g:rst_syntax_code_list = []

Because who knows what funky side-effects the other syntax files cause...

Answer 2

If one inlines grammars from other languages in for example markdown files, then the settings of those languages seem to override the settings for markdown syntax. One can check if that is the case using:

:verbose set iskeyword?

In order to fix this, one can define an auto command to be run each time one enters a markdown file (and probably other languages as well):

autocmd BufEnter,BufNewFile *.md set iskeyword=38,42,43,45,47-58,60-62,_,@

Putting this in my .vimrc fixed the issue for me. I was using vim-pandoc syntax and inlined languages including racket, python, sh and some. I think it is not necessary to define an auto command for leaving markdown files, because when you enter files of other languages, their syntax files should set their keywords, if I understand correctly.