bug#67310: [PATCH] Include the project--list as history when prompting for a project

[Eli Zaretskii]

> From: Spencer Baugh <sbaugh@janestreet.com>
> Cc: 67310@debbugs.gnu.org,  eliz@gnu.org,  juri@linkov.net
> Date: Wed, 22 Nov 2023 18:14:56 -0500
> 
>  (defvar project--list 'unset
> -  "List structure containing root directories of known projects.
> -With some possible metadata (to be decided).")
> +  "List of root directories of known projects.
> +
> +This is also the minibuffer history variable for
> +`project-prompt-project-dir' and `project-prompt-project-name'.")

Please add here cross-reference(s) to command(s) or option(s) used for
minibuffer-history handling.  IOW, don't assume that when you say
"minibuffer history variable", the reader immediately understands what
you mean and how this aspect is significant.

I also question the decision of making this variable an internal one.
I don't think any other minibuffer-history variables we have are
internal ones, and for good reasons.

> +      (let q((history-delete-duplicates t)
              ^^^
Typo?

> +            ;; Iterate in reverse order so project--name-history is in
> +            ;; the correct order.

What is the "correct" order?

> -              (if-let (proj (project--find-in-directory dir))
> -                  (push (cons (project-name proj) proj) ret)))
> +              (when-let (proj (project--find-in-directory dir))
> +                (let ((name (project-name proj)))
> +                  (push name project--name-history)
> +                  (push (cons name proj) ret))))

Not sure I understand why you replaced if-let with when-let here.

> +            (let ((history-add-new-input nil))

Why this non-standard way of let-binding a variable to nil?

> +        (let ((history-delete-duplicates t)
> +              (history-length t))
> +          (add-to-history 'project--list root))

Why are you overriding the values of these two user options?

> -  (let ((dirs (if recursive
> -                  (directory-files-recursively dir "" t)
> -                (directory-files dir t)))
> -        (known (make-hash-table :size (* 2 (length project--list))
> -                                :test #'equal))
> -        (count 0))
> -    (dolist (project (mapcar #'car project--list))
> +  (let* ((dirs (if recursive
> +                   (directory-files-recursively dir "" t)
> +                 (directory-files dir t)))
> +         (roots (project-known-project-roots))
> +         (known (make-hash-table :size (* 2 (length roots))
> +                                 :test #'equal))
> +         (count 0))

Is it really necessary to use let* here?

Thanks.