#+TITLE:   completion/selectrum
#+DATE:    February 16, 2021
#+SINCE:   v3.0.0
#+STARTUP: inlineimages

* Table of Contents :TOC_2:noexport:
- [[#description][Description]]
  - [[#module-flags][Module Flags]]
  - [[#plugins][Plugins]]
- [[#prerequisites][Prerequisites]]
- [[#features][Features]]
  - [[#jump-to-navigation][Jump-to navigation]]
  - [[#project-search--replace][Project search & replace]]
  - [[#in-buffer-searching][In-buffer searching]]
  - [[#selectrum-integration-for-various-completing-commands][Selectrum integration for various completing commands]]
  - [[#orderless-filtering][Orderless filtering]]

* Description
This module provides Selectrum integration for a variety of Emacs commands, as
well as a unified interface for project search and replace, powered by ripgrep.

#+begin_quote
TODO
#+end_quote

** Module Flags
+ ~+prescient~ Enables prescient filtering and sorting for Selectrum searches
  instead of orderless.

** Plugins
[[https://github.com/minad/vertico][vertico]] (~+vertico~, experimental for the moment)
[[https://github.com/raxod502/selectrum][selectrum]]
[[https://github.com/minad/consult][consult]]
[[https://github.com/oantolin/embark/][embark]]
[[https://github.com/oantolin/embark/][embark-consult]]
[[https://github.com/minad/marginalia][marginalia]]
[[https://github.com/oantolin/orderless][orderless]] (unless ~+prescient~)
[[https://github.com/mhayashi1120/Emacs-wgrep][wgrep]]
[[https://github.com/raxod502/prescient.el][prescient]] (~+prescient~)
[[https://github.com/minad/consult/][consult-flycheck]] (~:checkers syntax~)

* Prerequisites
This module has no prerequisites.

* Features

The packages in this module modify and use the built-in ~completing-read~
function, which is used by any function that requires completion. Due to this
the full scope of these packages is too large to cover here and you are
encouraged to go and read their excellent documentation. We will detail
Doom-specific additions:

** Jump-to navigation
This module provides an interface to navigate within a project using
=projectile=:

https://assets.doomemacs.org/completion/selectrum/projectile.png

| Keybind              | Description                         |
|----------------------+-------------------------------------|
| =SPC p f=, =SPC SPC= | Jump to file in project             |
| =SPC f f=, =SPC .=   | Jump to file from current directory |
| =SPC s i=            | Jump to symbol in file              |

** Project search & replace
This module provides interactive text search and replace using ripgrep.

| Keybind   | Description              |
|-----------+--------------------------|
| =SPC s p= | Search project           |
| =SPC s P= | Search another project   |
| =SPC s d= | Search this directory    |
| =SPC s D= | Search another directory |

https://assets.doomemacs.org/completion/selectrum/search.png

Prefixing these keys with the universal argument (=SPC u= for evil users; =C-u=
otherwise) changes the behavior of these commands, instructing the underlying
search engine to include ignored files.

This module also provides Ex Commands for evil users:

| Ex command             | Description                                                      |
|------------------------+------------------------------------------------------------------|
| ~:pg[rep][!] [QUERY]~  | Search project (if ~!~, include hidden files)                    |
| ~:pg[rep]d[!] [QUERY]~ | Search from current directory (if ~!~, don't search recursively) |

The optional `!` is equivalent to the universal argument for the previous
commands.

-----

These keybindings are available while a search is active:

| Keybind             | Description                                        |
|---------------------+----------------------------------------------------|
| =C-;=, =<leader> a= | Open an ~embark-act~ menu to chose a useful action |
| =C-c C-;=           | Open a buffer with your search results             |
| =C-c C-e=           | Open a writable buffer of your search results      |
| =C-SPC=             | Preview the current candidate                      |
| =C-M-j=             | Scroll down and preview.                           |
| =C-M-k=             | Scroll up and preview.                             |
| =C-RET=             | Open the selected candidate in other-window        |

Changes to the resulting wgrep buffer (opened by =C-c C-e=) can be committed
with =C-c C-c= and aborted with =C-c C-k= (alternatively =ZZ= and =ZQ=, for evil
users).

https://assets.doomemacs.org/completion/selectrum/search-replace.png

** In-buffer searching
This module provides some in buffer searching bindings:

+ =SPC s s= (~isearch~)
+ =SPC s S= (~+selectrum/search-symbol-at-point~ via ~consult-line~)
+ =SPC s b= (~consult-line~)

https://assets.doomemacs.org/completion/selectrum/buffer-search.png

An ~occur-edit~ buffer can be opened from ~consult-line~ with =C-c C-e=.

** Selectrum integration for various completing commands
*** General
| Keybind        | Description                   |
|----------------+-------------------------------|
| =M-x=, =SPC := | Enhanced M-x                  |
| =SPC '=        | Resume last Selectrum session |

*** Jump to files, buffers or projects
| Keybind              | Description                           |
|----------------------+---------------------------------------|
| =SPC RET=            | Find bookmark                         |
| =SPC f f=, =SPC .=   | Browse from current directory         |
| =SPC p f=, =SPC SPC= | Find file in project                  |
| =SPC f r=            | Find recently opened file             |
| =SPC p p=            | Open another project                  |
| =SPC b b=, =SPC ,=   | Switch to buffer in current workspace |
| =SPC b B=, =SPC <=   | Switch to buffer                      |

=SPC b b= and =SPC ,= support changing the workspace you're selecting a buffer from
via [[https://github.com/minad/consult#narrowing-and-grouping][Consult narrowing]], e.g. if you're on the first workspace, you can switch to
selecting a buffer from the third workspace by typing =3 SPC= into the prompt,
or the last workspace by typing =0 SPC=.

=SPC f f= and =SPC .= support exporting to a =wdired= buffer using =C-c C-e=.

*** Search
| Keybind   | Description                               |
|-----------+-------------------------------------------|
| =SPC p t= | List all TODO/FIXMEs in project           |
| =SPC s b= | Search the current buffer                 |
| =SPC s d= | Search this directory                     |
| =SPC s D= | Search another directory                  |
| =SPC s i= | Search for symbol in current buffer       |
| =SPC s p= | Search project                            |
| =SPC s P= | Search another project                    |
| =SPC s s= | Search the current buffer (incrementally) |

** Orderless filtering
When using orderless to filter through candidates, the default behaviour is for
each space separated input to match the candidate as a regular expression or
literally.

Note that due to this style of matching, pressing tab does not expand the input
to the longest matching prefix (like shell completion), but rather uses the
first matched candidate as input. Filtering further is instead achieved by
pressing space and entering another input. In essence, when trying to match
=foobar.org=, instead of option 1., use option 2.:

1. (BAD) Enter =foo TAB=, completes to =foobar.=, enter =org RET=
2. (GOOD) Enter =foo SPC org RET=

Doom has some builtin [[https://github.com/oantolin/orderless#style-dispatchers][style dispatchers]] for more finegrained filtering, which
you can use to further specify each space separated input in the following ways:
| Input            | Description                                |
|------------------+--------------------------------------------|
| =!foo=           | match without literal input =foo=          |
| =`bar= or =bar`= | match input =bar= as an initialism         |
| ==baz= or =baz== | match only with literal input =baz=        |
| =~qux= or =qux~= | match input =qux= with fuzzy/flex matching |