Change spell check word separator

Question

I want to change the characters, spell checking considers to being separating words.

I already have the following line in my ~/.vimrc file, which makes w and b recognize words with a - in between as one word:

 autocmd BufEnter,BufNewFile,TabEnter *.md set iskeyword=38,42,43,45,47-57,60-62,_,@

According to ASCII the 45 is the - character. However, spell checking seems to use another list of characters. When I write something like:

abc-def

I want it to be considered one word only, so that I may add this word to my word list as a correct word, instead of one of the parts abc or def being marked as a spelling mistake.

Is this possible? If it is, how?

Answer 1

Looks like you can't do this, see :h spell.txt (emphasis mine):

WORDS

Vim uses a fixed method to recognize a word. This is independent of 'iskeyword', so that it also works in help files and for languages that include characters like '-' in 'iskeyword'. The word characters do depend on 'encoding'.