spacemacs/layers/+vim/evil-snipe/README.org

#+TITLE: Evil-snipe layer
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[[file:img/Cat_With_Rifle.jpg]]

* Table of Contents                                         :TOC_4_org:noexport:
 - [[Description][Description]]
 - [[Install][Install]]
   - [[Layer][Layer]]
   - [[Improved f and t search behavior][Improved f and t search behavior]]
   - [[Two-character search with s][Two-character search with s]]
   - [[More scopes][More scopes]]
   - [[Symbol groups][Symbol groups]]
 - [[Key bindings][Key bindings]]

* Description
The package [[https://github.com/hlissner/evil-snipe][evil-snipe]]
- enables more efficient searches with ~f~ / ~F~ / ~t~ / ~T~.
- adds a new, more precise search with ~s/S~

Evil-snipe allows you to search more quickly and precisely in the buffer. It
does so by improving on the built in ~f~ / ~F~ / ~t~ / ~T~ searches and adding another
search command, namely ~s~ / ~S~.

=evil-snipe= changes ~s/S~ behavior in order to search forward/backwards in the
buffer with two chars.

* Install
** Layer
To use this configuration layer, add it to your =~/.spacemacs=. You will need to
add =evil-snipe= to the existing =dotspacemacs-configuration-layers= list in this
file.

** Improved f and t search behavior
With evil-snipe you can define your own search scope for ~f~ and ~t~ searches
which means that you won't have to jump to the correct line before searching
with ~f~ / ~t~ / ~F~ / ~T~. And after you have found a match, you can just press
~f~ or ~t~ again afterwards to continue the search. No need to use ~;~ / ~​,​~.

This alternate behavior is disabled by default, to enable it set the
layer variable =evil-snipe-enable-alternate-f-and-t-behaviors= to =t=:

#+BEGIN_SRC emacs-lisp
  (setq-default dotspacemacs-configuration-layers
    '((evil-snipe :variables evil-snipe-enable-alternate-f-and-t-behaviors t)))
#+END_SRC

** Two-character search with s
With the ~s~/~S~ keys you can do a simple search like ~f~/~t~, but instead of
searching for one character, you search for two. This makes the search a lot
more precise than regular ~f~/~t~ searches. While you can search forward or
backwards in the buffer with ~/~ and ~?~, ~s~ / ~S~ are much easier to reach,
don't require you to press enter and they are precise enough for many common
purposes.

** More scopes
Evil-snipe also adds several scope options for searches (set =evil-snipe-scope=
and =evil-snipe-repeat-scope= to one of these, the default value is =buffer=):

| Value         | Description                                                              |
|---------------+--------------------------------------------------------------------------|
| buffer        | search in the rest of the buffer after the cursor (=vim-sneak= behavior) |
| line          | search in the current line after the cursor (=vim-seek= behavior)        |
| visible       | search in the rest of the visible buffer only                            |
| whole-line    | same as =line=, but highlight matches on either side of cursor           |
| whole-buffer  | same as =buffer=, but highlight *all* matches in buffer                  |
| whole-visible | same as 'visible, but highlight *all* visible matches in buffer          |

If you do not want to replace the regular ~f~ / ~F~ / ~t~ / ~T~ behavior, just
remove this line from =evil-snipe/packages.el=:
=(evil-snipe-replace-evil)=

** Symbol groups
With symbol groups you can let a character stand for a regex, for example a
group of characters. By adding a pair of =(CHAR REGEX)= to the list
=evil-snipe-aliases= you can search for a regex very simply:

- Here we set the ~[~ character to mean =all characters [({= *in all modes* so a search
with ~sa[~ would find ~a[~, ~a{~ or ~a(~.

#+BEGIN_SRC emacs-lisp
  ;; Alias [ and ] to all types of brackets
  (push '(?\[ "[[{(]") evil-snipe-aliases)
  (push '(?\] "[]})]") evil-snipe-aliases)
#+END_SRC

- Here we set the char ~:~ to mean =a regex matching python function definitions= (but only in python-mode), so by searching with ~f:fff~ you can quickly cycle through
all function definitions in a buffer!

#+BEGIN_SRC emacs-lisp
  ;; For python style functions
  (add-hook 'python-mode-hook
            (lambda ()
              (make-variable-buffer-local 'evil-snipe-aliases)
              (push '(?: "def .+:") evil-snipe-aliases)))
#+END_SRC

* TODO Key bindings