GNU ELPA - isearch-mb

During a search, isearch-mb-minibuffer-map is active. By default, it includes the following commands:

• C-s, ↓: Repeat search forwards.
• C-r, ↑: Repeat search backwards.
• M-<: Go to first match (or n-th match with numeric argument).
• M->: Go to last match (or n-th last match with numeric argument).
• C-v, <next>: Search forward from the bottom of the window.
• M-v, <prior>: Search backward from the top of the window.
• M-%: Replace occurrences of the search string.
• C-M-%: Replace occurrences of the search string (regexp mode).
• M-s prefix: similar to standard isearch.

Everything else works as in a plain minibuffer. For instance, RET ends the search normally and C-g cancels it.

isearch provides a myriad of customization options, and most of them make just as much sense when using isearch-mb. The following are some uncontroversial improvements of the defaults:

(setq-default
 ;; Show match count next to the minibuffer prompt
 isearch-lazy-count t
 ;; Don't be stingy with history; default is to keep just 16 entries
 search-ring-max 200
 regexp-search-ring-max 200)

Note that since isearch-mb relies on a regular minibuffer, you can use you favorite tool to browse the history of previous search strings (say, the consult-history command from the excellent Consult package).

Using regexp search by default is a popular option as well:

(global-set-key (kbd "C-s") 'isearch-forward-regexp)
(global-set-key (kbd "C-r") 'isearch-backward-regexp)

Another handy option is to enable lax whitespace matching in one of the two variations indicated below. You can still toggle strict whitespace matching with M-s SPC during a search, or escape a space with a backslash to match it literally.

(setq-default
 isearch-regexp-lax-whitespace t
 ;; Swiper style: space matches any sequence of characters in a line.
 search-whitespace-regexp ".*?"
 ;; Alternative: space matches whitespace, newlines and punctuation.
 search-whitespace-regexp "\\W+")

Finally, you may want to check out the isearch-mb wiki for additional tips and tricks.

Some third-party isearch extensions require a bit of configuration in order to work with isearch-mb. There are three cases to consider:

• Commands that start a search in a special state shouldn't require extra configuration. This includes PDF Tools, Embark, etc.

• Commands that operate during a search session should be added to the list isearch-mb--with-buffer. Examples of this case are loccur-isearch and consult-isearch.

  (add-to-list 'isearch-mb--with-buffer #'loccur-isearch)
  (define-key isearch-mb-minibuffer-map (kbd "C-o") #'loccur-isearch)
  
  (add-to-list 'isearch-mb--with-buffer #'consult-isearch)
  (define-key isearch-mb-minibuffer-map (kbd "M-r") #'consult-isearch)
  

  Most isearch commands that are not made available by default in isearch-mb can also be used in this fashion:

  (add-to-list 'isearch-mb--with-buffer #'isearch-yank-word)
  (define-key isearch-mb-minibuffer-map (kbd "M-s C-w") #'isearch-yank-word)
  

• Commands that end the isearch session should be added to the list isearch-mb--after-exit. Examples of this case are anzu-isearch-query-replace and consult-line:

  (add-to-list 'isearch-mb--after-exit #'anzu-isearch-query-replace)
  (define-key isearch-mb-minibuffer-map (kbd "M-%") 'anzu-isearch-query-replace)
  
  (add-to-list 'isearch-mb--after-exit #'consult-line)
  (define-key isearch-mb-minibuffer-map (kbd "M-s l") 'consult-line)
  

  Making motion commands quit the search as in standard isearch is out of the scope of this package, but you can define your own commands to emulate that effect. Here is one possibility:

  (defun move-end-of-line-maybe-ending-isearch (arg)
  "End search and move to end of line, but only if already at the end of the minibuffer."
    (interactive "p")
    (if (eobp)
        (isearch-mb--after-exit
         (lambda ()
  	 (move-end-of-line arg)
  	 (isearch-done)))
      (move-end-of-line arg)))
  
  (define-key isearch-mb-minibuffer-map (kbd "C-e") 'move-end-of-line-maybe-ending-isearch)
  

Discussions, suggestions and code contributions are welcome! Since this package is part of GNU ELPA, contributions require a copyright assignment to the FSF.