Emacs functions for searching for a regex in a region and dumping the results in a temp buffer

reseq.el

;; This function stolen from https://emacs.stackexchange.com/a/7150/12219
(defun re-seq (regexp string)
  "Get a list of all regexp matches in a string"
  (save-match-data
    (let ((pos 0)
          matches)
      (while (string-match regexp string pos)
        (push (match-string 0 string) matches)
        (setq pos (match-end 0)))
      matches)))

(require 'cl)
(defun re-seq-in-region-unique (start end regex)
  "Select a region and enter a regex to search for. Results will be dumped in a temp buffer."
  (interactive "r \nsRegex: ")
  (with-output-to-temp-buffer (make-temp-name "re-seq-results")
    (let ((matches (remove-duplicates
                    (re-seq regex (buffer-substring-no-properties start end))
                    :test (lambda (x y) (or (null y) (equal x y))))))
      (while matches
        (princ (concat (car matches) "\n"))
        (setq matches (cdr matches))))))