Please make it to work with eglot

[arbv]

When being used with Eglot the current version fails with the following error message:

imenu-list--current-entry: Wrong type argument: number-or-marker-p, [(:children [(:kind 10 :name "UDP" :range (:end (:character 18 :line 33) :start (:character 15 :line 33)) :selectionRange (:end (:character 18 :line 33) :start (:character 15 :line 33)) :containerName "(anonymous enum)") (:kind 10 :name "TCP" :range (:end (:character 23 :line 33) :start (:character 20 :line 33)) :selectionRange (:end (:character 23 :line 33) :start (:character 20 :line 33)) :containerName "(anonymous enum)") (:kind 10 :name "DOT" :range (:end (:character 28 :line 33) :start (:character 25 :line 33)) :selectionRange (:end (:character 28 :line 33) :start (:character 25 :line 33)) :containerName "(anonymous enum)") (:kind 10 :name "DOH" :range (:end (:character 33 :line 33) :start (:character 30 :line 33)) :selectionRange (:end (:character 33 :line 33) :start (:character 30 :line 33)) :containerName "(anonymous enum)")] :kind 10 :name "(anonymous enum)" :range (:end (:character 35 :line 33) :start (:character 8 :line 33)) :selectionRange (:end (:character 12 :line 33) :start (:character 8 :line 33)))] [3 times]

I needed to write my own custom position translator. Here are the relevant parts of my config:

(defun eglot/position-translator ()
  (lambda (e)
    (let* ((range (plist-get (aref e 0) :range))
           (start (plist-get range :start)))
      (when (fboundp #'eglot--lsp-position-to-point)
        (eglot--lsp-position-to-point start t)))))

(defun imenu-list/enable-eglot-position-translator ()
  (interactive)
  (when (and (fboundp #'eglot-managed-p)
             (eglot-managed-p))
    (setq-local imenu-list-custom-position-translator
                'eglot/position-translator)))

(defun imenu-list/eglot-toggle ()
  (interactive)
  (imenu-list/enable-eglot-position-translator)
  (imenu-list-smart-toggle))

;; imenu-list to browse tags
(global-set-key (kbd "<f9>") 'imenu-list/eglot-toggle)

Please adapt the code to include it into a forthcoming version.

[muffinmad]

Maybe related to #58

[arbv]

It seems so, especially taking into account this reply from eglot author in another issue.

[bmag]

Thanks for raising this issue. Indeed it is a continuation of #58.

I'd like to add a case for Eglot in imenu-list-position-translator, however I'm not sure how to correctly detect when Eglot is used. Eglot doesn't set imenu-create-index-function to eglot-imenu. Instead, it relies on imenu-create-index-function being set to its default value (imenu-default-create-index-function), and adds eglot-imenu as a local :before-until advice to imenu-default-create-index-function. This means that if eglot-imenu returns nil, then the default non-Eglot index is created.

I think for detection, I can use the condition @arbv suggested:

(and (fboundp #'eglot-managed-p) (eglot-managed-p))

And the translator function will handle both Eglot and default imenu entries:

(defun get-eglot-position (pos)
  ;; when Eglot is in charge of Imenu, then the index is created by `eglot-imenu', with a fallback to
  ;; `imenu-default-create-index-function' when `eglot-imenu' returns nil. If POS is an array, it means
  ;; it was created by `eglot-imenu' and we need to extract its position. Otherwise, it was created by
  ;; `imenu-default-create-index-function' and we should return it as-is.
  (if (arrayp pos)
      (eglot--lsp-position-to-point (plist-get (plist-get (aref pos 0) :range) :start) t)
    pos))

[bmag]

I don't use Eglot. Can both of you test that #65 solves this issue? The code is liable to break with future changes of Eglot, but hopefully it won't happen often and the fixes will be simple.

[muffinmad]

@bmag Thanks! But why you rely on eglot? I think you can just call function with arguments if the element is looks like (INDEX-NAME POSITION FUNCTION ARGUMENTS...).

[bmag]

@muffinmad that function jumps to the entry's location, so using it means jumping to each entry and then jumping back, which I suspect will have a performance impact in buffers with a large index (especially when point is towards the end of the buffer). If you want to try this approach, evaluate the following code:

(defun imenu-list--current-entry-via-excursion ()
  (let ((point-pos (point-marker))
        (offset (point-min-marker))
        match-entry)
    (dolist (entry imenu-list--line-entries match-entry)
      (unless (imenu--subalist-p entry)
        (let ((entry-pos (save-mark-and-excursion
                           (imenu entry)
                           (point))))          
          (when (imenu-list-<= offset entry-pos point-pos)
            (setq offset entry-pos)
            (setq match-entry entry)))))))

(advice-add #'imenu-list--current-entry :override #'imenu-list--current-entry-via-excursion)

;; to disable:
;; (advice-remove #'imenu-list--current-entry #'imenu-list--current-entry-via-excursion)

[muffinmad]

@bmag Right, I've completely forgot about the current function highlighting.

[arbv]

@bmag

I have not tested the whole package with the changes that you have suggested in #65, but the function imenu-list--translate-eglot-position works fine when being used in my configuration file.

So, I would say it is safe to merge.

Thanks for addressing this issue!