bug#45134: Add project-switch-project-by-name

[Rudolf Schlatte]

Dmitry Gutov <dgutov@yandex.ru> writes:

> On 09.12.2020 17:14, Rudolf Schlatte wrote:
>> Certain “dashboard-type” packages present a list of projects and let the
>> user switch to one of them.  In that case, the project root is already
>> known, and project.el only needs to present the dispatch menu of
>> ‘project-switch-commands’.
>
> So the idea is you know the directory in advance and only need to show
> the dispatch menu?

Yes, exactly.

> How about this instead?

Tested and works as expected, both invoked with ‘C-x p p’ where it
prompts for a project first, and from dashboard where it shows the
dispatch menu immediately for the chosen project.  Very nice!

> diff --git a/lisp/progmodes/project.el b/lisp/progmodes/project.el
> index 449eadc3de..f7c6a55f44 100644
> --- a/lisp/progmodes/project.el
> +++ b/lisp/progmodes/project.el
> @@ -1275,13 +1275,13 @@ project--keymap-prompt
>     "  "))
>
>  ;;;###autoload
> -(defun project-switch-project ()
> +(defun project-switch-project (dir)
>    "\"Switch\" to another project by running an Emacs command.
>  The available commands are presented as a dispatch menu
>  made from `project-switch-commands'."
> -  (interactive)
> -  (let ((dir (project-prompt-project-dir))
> -        (choice nil))
> +  (interactive
> +   (list (project-prompt-project-dir)))
> +  (let ((choice nil))
>      (while (not choice)
>        (setq choice (assq (read-event (project--keymap-prompt))
>                           project-switch-commands)))