Re: Turning on/off tree-sitter modes

[Dmitry Gutov <dmitry@gutov.dev>]

On 25/11/2024 14:09, Eli Zaretskii wrote:
>> Date: Mon, 25 Nov 2024 02:44:52 +0200
>> Cc: johan.myreen@gmail.com, emacs-devel@gnu.org
>> From: Dmitry Gutov <dmitry@gutov.dev>
>>
>> On 24/11/2024 20:56, Eli Zaretskii wrote:
>>>>     major-mode-remap-alist:
>>>>     INS DEL Key: js-mode
>>>>             Value: js-ts-mode
>>>>     INS DEL Key: ruby-mode
>>>>             Value: ruby-ts-mode
>>> In addition, I personally find this UI quite perplexing, and kinda
>>> doubt users who use it will understand what "Key" and "value" mean in
>>> this case.
>>
>> We could add more detailed annotations to those customization fields, so
>> it could look more like this, for example:
>>
>>     Major Mode Remap Alist:
>>     Repeat:
>>     INS DEL Cons-cell:
>>                 Mode to map from: js-mode
>>                 Function to call instead: js-ts-mode
> 
> I think this would be a big step in the right direction.
> 
> Bonus points for replacing "Repeat" and "Cons-cell" with something
> more user-friendly, like "Set of remappings" and "Remap", for example.

Maybe like this:

   Major Mode Remap Alist:
   List of remappings:
   INS DEL Remap:
               From major mode: js-mode
               To mode (or function): js-ts-mode


diff --git a/lisp/files.el b/lisp/files.el
index 9c105dbe1a5..879faa563ad 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -3606,7 +3606,10 @@ major-mode-remap-alist
  FUNCTION is typically a major mode which \"does the same thing\" as
  MODE, but can also be nil to hide other entries (either in this var or
  in `major-mode-remap-defaults') and means that we should call MODE."
-  :type '(alist (symbol) (function)))
+  :type '(repeat :tag "List of remappings"
+          (cons :tag "Remap"
+           (symbol :tag "From major mode")
+           (function :tag "To mode (or function)"))))

  (defvar major-mode-remap-defaults nil
    "Alist mapping file-specified modes to alternative modes.