* :completion ivy

This module adds the Ivy completion backend.

I prefer ivy over ido and helm, for its speed and simplicity. With ivy's help and some hackery, I get the following features:

+ Project-wide search & replace powered by ~rg~ (falls back to ~ag~)
+ Project jump-to navigation ala Command-T, Sublime Text's Jump-to-anywhere or Vim's CtrlP plugin.
+ Ivy integration for ~M-x~, ~imenu~, ~recentf~ and others.
+ A powerful, interactive in-buffer search using ~swiper~.
+ Ivy-powered TODO/FIXME navigation

** Install
This module optionally depends on [[https://github.com/BurntSushi/ripgrep][ripgrep]] and [[https://github.com/ggreer/the_silver_searcher][the_silver_searcher]].

~rg~ is faster, but its results aren't deterministic and it doesn't support multiline search or full PCRE, that's where ~ag~ is useful.

*** MacOS
#+BEGIN_SRC sh :tangle (if (doom-system-os 'macos) "yes")
brew install ripgrep the_silver_searcher
#+END_SRC

*** Arch Linux
#+BEGIN_SRC sh :dir /sudo:: :tangle (if (doom-system-os 'arch) "yes")
sudo pacman --needed --noconfirm -S ripgrep the_silver_searcher
#+END_SRC

** Usage
*** Search & Replace
A project-wide search can be performed with Ag (the silver searcher) or Rg
(ripgrep) via their ex commands: ~:ag[!]~ and ~:rg[!]~ (or their
current-directory counterparts ~:agcwd[!]~ and ~:rgcwd[!]~)

[[/../screenshots/modules/completion/ivy/ivy-search.gif]]

From this session, you can press =Shift + Tab= to create an writeable occur
buffer in wgrep mode.

[[/../screenshots/modules/completion/ivy/ivy-search-replace.gif]]

Make your modifications and press =C-c C-c= to commit them, or =C-c C-k= to
abort.

*** Jump-to-file project navigation
Inspired by Sublime Text's jump-to-anywhere, Vim's CtrlP or Unite plugins, and
Textmate's Command-T, a marriage of ~projectile~ and ~ivy~ makes this available
to you in Emacs. Invoke it with =<leader> /= or ~counsel-projectile-find-file~.

[[/../screenshots/modules/completion/ivy/ivy-projectile.gif]]

*** In-buffer searching
I prefer to use ~evil-search~ (invoked by pressing =/= in normal mode) when
jumping small/moderate (or predictable) distances. On occasion I need more
feedback, so I turn to ~swiper~ (available directly with =M-x swiper RET=, or
via ~:sw[iper]~).

[[/../screenshots/modules/completion/ivy/ivy-swiper.gif]]

*** TODO-Task lookup
I sprinkle my projects with TODO's & FIXME's. Using ivy and ripgrep, I wrote
~+ivy/tasks~ to help me navigate to them. It can be invoked via ~:todo[!]~ as
well.

[[/../screenshots/modules/completion/ivy/ivy-todo.gif]]

** Appendix
*** Commands & Keybindings
Here is a list of my commonly used commands, their default keybinds (defined in
[[../../private/hlissner/+bindings.el][private/hlissner/+bindings.el]]), and their corresponding ex command (defined in
[[../../private/hlissner/+commands.el][private/hlissner/+commands.el]]).

| command                             | key / ex command    | description                                                      |
|-------------------------------------+---------------------+------------------------------------------------------------------|
| ~counsel-M-x~                       | =M-x=               | Smarter, smex-powered M-x                                        |
| ~counsel-bookmark~                  | =<leader> b=        | Find bookmark                                                    |
| ~counsel-find-file~                 | =<leader> .=        | Browse from current directory                                    |
| ~counsel-projectile-find-file~      | =<leader> /=        | Find file in project                                             |
| ~counsel-projectile-switch-project~ | =<leader> p=        | Open another project                                             |
| ~counsel-recentf~                   | =<leader> r=        | Find recently opened file                                        |
| ~+ivy/switch-buffer~                | =<leader> ,=        | Jump to buffer in current workspace                              |
| ~+ivy/switch-workspace-buffer~      | =<leader> <=        | Jump to buffer across workspaces                                 |
| ~+ivy:ag~                           | ~:ag[!] [QUERY]~    | Search project (BANG = ignore gitignore)                         |
| ~+ivy:ag-cwd~                       | ~:agcwd[!] [QUERY]~ | Search this directory (BANG = don't recurse into subdirectories) |
| ~+ivy:rg~                           | ~:rg[!] [QUERY]~    | Search project (if BANG, ignore gitignore)                       |
| ~+ivy:rg-cwd~                       | ~:rgcwd[!] [QUERY]~ | Search this directory (BANG = don't recurse into subdirectories) |
| ~+ivy:swiper~                       | ~:sw[iper] [QUERY]~ | Search current buffer                                            |
| ~+ivy:todo~                         | ~:todo[!]~          | List all TODO/FIXMEs in project (or current file if BANG)        |

While in a search (e.g. invoked from ~+ivy:ag~ or ~+ivy:rg~), these new
keybindings are available to you:

| key         | description                                                                    |
|-------------+--------------------------------------------------------------------------------|
| =<backtab>= | Perform search/replace on the search results (open occur buffer in wgrep mode) |
| =C-SPC=     | Preview the current candidate                                                  |
| =M-RET=     | Open the selected candidate in other-window                                    |

*** Hacks
+ Where possible, functions with ivy/counsel equivalents have been remapped
  (like ~find-file~ => ~counsel-find-file~). So a keybinding to ~find-file~ will
  invoke ~counsel-find-file~ instead.
+ ~counsel-[arp]g~'s 3-character limit was reduced to 1 (mainly for the ex command)
+ ~counsel-[arp]g~'s parentheses quoting behavior was reversed. Now, if you
  want literal parentheses, you must escape them: e.g. ~\(match\)~ is literal,
  ~(match)~ is a regexp group.