On Mon, Jul 12, 2021 at 3:46 PM Tassilo Horn <t...@gnu.org> wrote: > > Hongyi Zhao <hongyi.z...@gmail.com> writes: > >> (delq nil (mapcar (lambda (buf) > >> (with-current-buffer buf > >> (when (eq major-mode 'LaTeX-mode) > >> (cons (buffer-file-name buf) > >> (TeX-master-file "pdf"))))) > >> (buffer-list))) > >> nil > > > > This is just out of the curiosity about the behavior of the `delq' > > built-in function used above. According to the built-in document: > > (delq nil '(nil 1 nil)) ;=> (1) > (delq nil '(nil nil nil)) ;=> nil, aka, the empty list () > (eq nil '()) ;=> t
Got it. The `nil' shown in my example just means the empty result list (). The `nil' in itself can be used in different context, when it's used as boolean variable, it means false. But it can also be used to represent an empty list (). Regards -- Assoc. Prof. Hongyi Zhao <hongyi.z...@gmail.com> Theory and Simulation of Materials Hebei Vocational University of Technology and Engineering No. 473, Quannan West Street, Xindu District, Xingtai, Hebei province
