#+TITLE:   completion/helm
#+DATE:    January 22, 2021
#+SINCE:   v2.0
#+STARTUP: inlineimages

* Table of Contents :TOC_3: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]]
    - [[#search][Search]]
    - [[#replace][Replace]]
  - [[#in-buffer-searching][In-buffer searching]]
  - [[#helm-integration-for-various-completing-commands][Helm integration for various completing commands]]
    - [[#general][General]]
    - [[#jump-to-files-buffers-or-projects][Jump to files, buffers or projects]]
    - [[#search-1][Search]]
- [[#configuration][Configuration]]
  - [[#icons][Icons]]
  - [[#posframe][Posframe]]
- [[#troubleshooting][Troubleshooting]]

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

#+begin_quote
I prefer ivy over ido for its flexibility. I prefer ivy over helm because it's
lighter, simpler and faster in many cases.
#+end_quote

Ivy is considered a first-class citizen in Doom, however it is still possible to use Helm if you so desire.

** Module Flags
+ =+fuzzy= Enables fuzzy completion for Helm searches.
+ =+childframe= Causes Helm to display in a floating child frame, above Emacs.
+ =+icons= Enables icons (supports both =all-the-icons= and =treemacs= icons)

** Plugins
+ [[https://github.com/emacs-helm/helm][helm]]
+ [[https://github.com/microamp/helm-rg][helm-rg]]
+ [[https://github.com/emacs-jp/helm-c-yasnippet][helm-c-yasnippet]]
+ [[https://github.com/tuhdo/helm-company][helm-company]]
+ [[https://github.com/emacs-helm/helm-describe-modes][helm-describe-modes]]
+ [[https://github.com/bbatsov/helm-projectile][helm-projectile]]
+ [[https://github.com/abo-abo/swiper-helm][helm-swiper]]
+ [[https://github.com/emacs-helm/helm-descbinds][helm-descbinds]]
+ [[https://github.com/PythonNut/helm-flx][helm-flx]]* (=+fuzzy=)
+ [[https://github.com/tumashu/helm-posframe][helm-posframe]]* (=+childframe=)
+ [[https://github.com/emacs-helm/helm-org][helm-org]]* (=:lang org=)
+ [[https://github.com/yyoncho/helm-icons][helm-icons]]* (=+icons=)

* Prerequisites
This module has no prerequisites.

* Features
Much like Ivy, Helm is a /large/ framework and as such
covering everything is not in scope, however a number
of Doom-specific features are shown below:

** Jump-to navigation
Similar to Ivy, this module provides an interface to
navigate within a project using =projectile=:

| 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 also provides interacetive text search and replace using ripgrep

*** Search

| 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 |
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.

*** Replace

These keybindings are available while a search is active:

| Keybind   | Description                                   |
|-----------+-----------------------------------------------|
| =C-c C-o= | 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-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).

** In-buffer searching
The =swiper= package provides an interactive buffer search powered by helm. It
can be invoked with:

+ =SPC s s= (~swiper-isearch~)
+ =SPC s S= (~swiper-isearch-thing-at-point~)
+ =SPC s b= (~swiper~)
+ ~:sw[iper] [QUERY]~

A wgrep buffer can be opened from swiper with =C-c C-e=.
** Helm integration for various completing commands
Helm also has a number of overrides for built-in functionality:

*** General
| Keybind    | Description               |
|------------+---------------------------|
| =M-x=, =SPC := | Smarter, smex-powered M-x |
| =SPC '=      | Resume last ivy 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                      |

*** 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) |

* Configuration
** Icons
Icons are now included, and support 2 providers ([[https://github.com/domtronn/all-the-icons.el][all-the-icons]] and [[https://github.com/Alexander-Miller/treemacs][treemacs]]).
By default, to maintain consistency we use =all-the-icons=; however if you wish
to modify this you can do so using the below snippet:

#+begin_src emacs-lisp
(after! helm
  (setq helm-icons-provider 'treemacs))
#+end_src

** Posframe

* Troubleshooting