print -r -- >&2"zsh-syntax-highlighting: '${highlighter}' highlighter should define both required functions '_zsh_highlight_highlighter_${highlighter}_paint' and '_zsh_highlight_highlighter_${highlighter}_predicate' in '${highlighter_dir}/${highlighter}-highlighter.zsh'."
print -r -- >&2"zsh-syntax-highlighting: ${(qq)highlighter} highlighter should define both required functions '_zsh_highlight_highlighter_${highlighter}_paint' and '_zsh_highlight_highlighter_${highlighter}_predicate' in ${(qq):-"$highlighter_dir/${highlighter}-highlighter.zsh"}."