toggle the mark ring. the best way is add a new action and mapping to =helm-source-mark-ring=, but
since there is no map such as =helm-mark-ring=map=, so I cannot binding a key to the quit action.
#+BEGIN_SRC emacs-lisp :tangle yes :results silent
+ (setq mark-ring-max 50)
(global-set-key (kbd "M-`") #'helm-mark-ring)
(define-key minibuffer-local-map (kbd "M-`") 'keyboard-escape-quit)
*** Kill ring
=helm-show-kill-ring=
#+BEGIN_SRC emacs-lisp :tangle yes :results silent
+ (setq kill-ring-max 100) ; default is 60p
(global-set-key (kbd "M-y") #'helm-show-kill-ring)
#+END_SRC
#+END_SRC
** Search & Replace / hightlight =M-s=
-*** search
+*** isearch
=C-s=, =C-r=,
=C-w= add word at point to search string,
=M-%= query replace
=C-y= yank from clipboard to search string
=M-n=, =M-p=, history
=C-M-i= complete search string
+set the isearch history size, the default is only =16=
+#+BEGIN_SRC emacs-lisp :tangle yes :results silent
+ (setq history-length 5000)
+ (set-variable regexp-search-ring-max 1000)
+ (set-variable search-ring-max 1000)
+#+END_SRC
*** =M-s= prefix
use the prefix =M-s= for searching in buffers