Let say I havelet l:letter = 'A'is there a function that takes l:letter ascii code and transforms it to 'B'? I mean something likelet l:next_letter = l:letter + 1I know there's <Ctrl-A> with set nf=alpha, but that requires to have the cursor over the character in the document and I was wondering if it's possible to do it with a variable without modifying the document.Here's what I try so far, but as I said, it modifies the document and the cursor position:fu! s:get_next_char(letter)    set nf=octal,hex,alpha    call setline(line('$') + 1, a:letter)    exe ':normal! G^'.\<C-A>    set nf=octal,hex    let l:next_letter = getline('$')    normal! Gdd    return l:next_letterendfu
Manipulate chars with their ascii code
vimscript
It's easy to do with :help nr2char() and :help char2nr().Example usage::let b_char = nr2char(char2nr('A') + 1)Then, :echo b_char will return 'B'