How can I search through registers via counsel?

Question

I need something like helm-register which lists all the registers and it can be searched through.

Answer 1

Latest version of counsel (version 20190522.2133 on MELPA) has counsel-register.

From the documentation:

counsel-register is an interactive, autoloaded function defined in
counsel.el.

Signature
(counsel-register)

Documentation
Interactively choose a register.

Key Bindings
This command is not in any keymaps.

References
counsel-register is unused in counsel.el.

Answer 2

How about this:

(defvar counsel-register-history nil
  "History for `counsel-register'.")

(defun counsel-register-action (s)
  "Default action for `counsel-register'.

Do what I mean for each type of register."
  (let* ((k (string-to-char s))
         (v (get-register k)))
    (if (or (stringp v) (numberp v))
        (insert (format "%s" v))
      (jump-to-register k))))

(defun counsel-register ()
  "Interactively choose a register and perform a default an action on it."
  (interactive)
  (ivy-read "Register: "
            (cl-loop for (k . v) in register-alist
                     collect (concat (key-description (list k))
                                     " => "
                                     (if (or (stringp v) (numberp v))
                                         (format "%s" v)
                                       (format "[%s] %s"
                                               (symbol-name (car v))
                                               (cdr v)))))
            :preselect 0
            :history 'counsel-register-history
            :action #'counsel-register-action))

Note that this solution does not search through bookmarks. But that would be easy to add. You just have to account for bookmarks-alist as well.