Andrew Tropin schreef op do 07-04-2022 om 20:01 [+0300]:
> Idk how file-exists? works internally, but still expect it to be more
> efficient than lstat.  That's why I decided to use lstat only as a
> "fallback" option in `or` statement.

Here's the definition, from module/ice-9/boot-9.scm (Guile source
code):

;; For reference, Emacs file-exists-p uses stat in this same way.
(define file-exists?
  (if (provided? 'posix)
      (lambda (str)
        (->bool (stat str #f)))
      [non-POSIX code that's not relevant to Guix]))

'file-exists?' just calls 'stat', a variant of 'lstat', so I don't
think there are performance gains to be had here.  Well, the
(stat ... #f) might not need to install an exception handler since it
is written in C, but that seems at most a micro-optimisation to me.

Greetings,
Maxime.