bug#74235: [PATCH] ; Remove 'nil' from some 'lua-ts-mode' options

[Eli Zaretskii <eliz@gnu.org>]

> From: john muhl <jm@pub.pink>
> Date: Wed, 06 Nov 2024 15:22:34 -0600
> 
> * lisp/progmodes/lua-ts-mode.el (lua-ts-luacheck-program):
> (lua-ts-inferior-program): Remove 'nil' as it is never a valid
> choice.  (Bug#74235)

IMO, the use of these options in the code is not clean: if these
programs are not installed, the commands which reference these options
will signal errors whose diagnostic might not clearly indicate the
root cause.  I would like to see a cleaner handling of such
contingencies by this mode.  Does this make sense, and if so, would
you like to suggest changes to that effect?

>  (defcustom lua-ts-luacheck-program "luacheck"
>    "Location of the Luacheck program."
> -  :type '(choice (const :tag "None" nil) string)
> +  :type 'string
>    :version "30.1")

I think if we require this to be the name of a program, 'file' is a
better value for :type, because it allows completion if the user types
an absolute file name.

>  (defcustom lua-ts-inferior-buffer "*Lua*"
> @@ -83,7 +83,7 @@ lua-ts-inferior-buffer
>  
>  (defcustom lua-ts-inferior-program "lua"
>    "Program to run in the inferior Lua process."
> -  :type '(choice (const :tag "None" nil) string)
> +  :type 'string
>    :version "30.1")
>  
>  (defcustom lua-ts-inferior-options '("-i")
> -- 
> 2.47.0
> 
> john muhl <jm@pub.pink> writes:
> 
> > Tags: patch
> >
> > For some silly reason the lua-ts-{inferior,luacheck}-program
> > options ended up with an option for “None”. Obviously setting your
> > Lua interpreter or linter program to nil is not going to work.
> >
> > Any chance it could make it into emacs-30?

lua-ts-mode is new in Emacs 30, so we can install these changes on the
release branch, as a stopgap.  But I'd like to see a cleaner solution
installed later, even if we decide to install that on master due to
its complexity.

Thanks.