tools/lookup: remove duplicate code & minor fixes

- Removes vestigial definition of +lookup/in-docsets, which would throw
  an error.
- Fixes the universal argument for this function.
- Fix multiple set-docsets! calls prepending rather than setting
  dash-docs-docsets.
- Logs search attempts for debugging purposes.

modules/tools/lookup/autoload/docsets.el

@@ -29,7 +29,7 @@ Used by `+lookup/in-docsets' and `+lookup/documentation'."
   (let ((action (if (keywordp (car docsets)) (pop docsets))))
     (dolist (mode (doom-enlist modes))
       (let ((hook (intern (format "%s-hook" mode)))
-            (fn (make-symbol (format "+lookup|init--%s-%s" (or action "set") mode))))
+            (fn (intern (format "+lookup|init--%s-%s" (or action "set") mode))))
         (if (null docsets)
             (remove-hook hook fn)
           (fset fn
@@ -84,9 +84,13 @@ If prefix ARG is supplied, search all installed installed docsets. They can be
 installed with `dash-docs-install-docset'."
   (interactive "P")
   (require 'dash-docs)
-  (let ((dash-docs-common-docsets (if arg dash-docs-common-docsets))
-        (dash-docs-docsets (cl-remove-if-not #'dash-docs-docset-path (or docsets dash-docs-docsets)))
+  (let ((dash-docs-common-docsets)
+        (dash-docs-docsets
+         (if arg
+             (dash-docs-installed-docsets)
+           (cl-remove-if-not #'dash-docs-docset-path (or docsets dash-docs-docsets))))
         (query (or query (+lookup-symbol-or-region) "")))
+    (doom-log "Searching docsets %s" dash-docs-docsets)
     (cond ((featurep! :completion helm)
            (helm-dash query))
           ((featurep! :completion ivy)

modules/tools/lookup/autoload/lookup.el

@@ -316,29 +316,3 @@ Otherwise, falls back on `find-file-at-point'."
                                  (run-hooks 'projectile-find-file-hook))))))
                          (#'doom-project-browse))))
              (find-file-at-point path))))))
-
-
-;;
-;;; Source-specific commands
-
-(defvar counsel-dash-docsets)
-(defvar helm-dash-docsets)
-;;;###autoload
-(defun +lookup/in-docsets (&optional query docsets)
-  "Looks up QUERY (a string) in available Dash docsets for the current buffer.
-
-DOCSETS is a list of docset strings. Docsets can be installed with
-`+lookup/install-docset'."
-  (interactive)
-  (let* ((counsel-dash-docsets
-          (unless (eq docsets 'blank)
-            (or docsets
-                (or (bound-and-true-p counsel-dash-docsets)
-                    (bound-and-true-p helm-dash-docsets)))))
-         (helm-dash-docsets counsel-dash-docsets)
-         (query (or query (+lookup-symbol-or-region) "")))
-    (cond ((featurep! :completion helm)
-           (helm-dash query))
-          ((featurep! :completion ivy)
-           (counsel-dash query))
-          ((user-error "No dash backend is installed, enable ivy or helm.")))))