Dmitry Gutov <dgutov@yandex.ru> writes:

> Hi Damien, thanks for the report.
>
> On 20/10/2023 14:48, Damien Cassou wrote:
>> the documentation of `project-remember-projects-under' is:
>>        "Index all projects below a directory DIR.  If RECURSIVE is
>>      non-nil, recurse into all subdirectories to find more projects.
>>      After finishing, a message is printed summarizing the progress.  The
>>      function returns the number of detected projects."
>> Regardless of the value of RECURSIVE, I understand from the above
>> that
>> all child directories of the DIR argument will be investigated. The doc
>> doesn't say anything about investigating if DIR is itself a project or
>> not so I think it would make sense if the function wasn't.
>> But the code says otherwise (as far as I understand it):
>> (defun project-remember-projects-under (dir &optional recursive)
>>    (let ((queue (list dir)))
>>      ;; …
>>      (while queue
>>        (when-let ((subdir (pop queue))
>>                   ((file-directory-p subdir)))
>>          ;; maybe register `subdir' as a project
>>          ;; …
>>          (when (and recursive (file-directory-p subdir))
>>            (setq queue (nconc (directory-files subdir …) queue)))))))
>> The code above seems to investigate DIR first and, if RECURSIVE is
>> non-nil, look at the directories below it.
>> Also, the second check (file-directory-p subdir) seems unnecessary
>> because of the first one.
>> There is a part of the code I don't understand:
>>    (unless (eq recursive 'in-progress)
>> It seems nowhere in the code nor in the documentation do we say
>> anything
>> about this 'in-progress special value. Is it a left over from a previous
>> (recursive) version of the algorithm?
>
> Philip, could you look into this?

One idea would be to just simplify the entire implementation by relying
on directory-files and directory-files-recursively.  Say something like
this: