Haskell Vim IDE

In less than ten minutes your Vim will transform into a beautiful Haskell paradise. (Don't worry, it backs up your original configuration to ~/.config/haskell-vim-now/backup/.vimrc.yearmonthdate_time.) It also builds all necessary support binaries including codex, hscope, ghc-mod, hasktags, hoogle and more.

No more wading through plugins trying to make them all work together. In ten minutes you will have a fully functional Vim that looks great and lets you

• inspect types
• evaluate Haskell
• lint and check
• manipulate tags
• hoogle lookup
• pointfree refactor
• tab complete
• unicode symbols
• highlight DSLs
• work with git

Installation

Just download and run the installer:

curl -L https://git.io/haskell-vim-now > /tmp/haskell-vim-now.sh
bash /tmp/haskell-vim-now.sh

WARNING: this command, once successful, will make backups and remove your existing VIM configurations (.vim, plugins etc). You can later customize HVN configurations.

Keybindings and commands

The commands are organized into logical groups to help you remember them.

Types, autocomplete, refactoring, and linting

<Tab>	Autocomplete with words in file
<C-space>	Autocomplete with symbols in your Cabal sandbox
,ht	Show type of expression under cursor
,hT	Insert type of expression into previous line
,hr	Apply one refactoring hint at cursor position
,hR	Apply all refactoring suggestions in the file
,hl	Run Haskell linter on file
,hc	Run Haskell compile check on file
,<cr>	Clear type selection

Hoogle

,hh	Run Hoogle on the word under the cursor
,hH	Run Hoogle and prompt for input
,hi	Run Hoogle for detailed information on word under cursor
,hI	Run Hoogle for detailed information and prompt for input
,hz	Close the Hoogle search window

GHCI repl

If you open a tmux terminal alongside MacVim then you can send Vim selections to it. This works well for evaluating things in GHCI.

,rs	Send selected text to tmux
,rv	Change tmux session, window, and pane attachment

Git

,g?	Last-committed files (Monday morning key)
,gs	Git status (fugitive)
,gg	Git grep
,gl	Git log (extradition)
,gd	Git diff
,gb	Git blame

Commenting

gc	Comment / Uncomment selection

Aligning

,a=	Align on equal signs
,a,	Align on commas
,a|	Align on vertical bar
,ap	Align on character of your choice

Splits and find file

,<space>	Fuzzy file find (CtrlP)
,f	Toggle file browser, find file
,F	Toggle file browser
,sj	Open split below
,sk	Open split above
,sh	Open split leftward
,sl	Open split rightward

Tags

,tg	Generate tags with codex
,tt	Open/close the tag bar
C-]	Jump to definition of symbol (codex + hasktags)	Note: You must generate the tags for your project (with ,tg) prior to using the jump command.
C-\	Show uses of symbol (hscope)

Conversions

,h.	Transform visual selection to pointfree style
,h>	Transform visual selection to pointed style

Buffers

,bp	Previous buffer
,bn	Next buffer
,b<space>	Buffer fuzzy finder
,bd	Delete buffer, keep window open (bbye)
,bo	Close all buffers except the current one

Misc

,ma	Enable mouse mode (default)
,mo	Disable mouse mode
,ig	Toggle indentation guides
,u	Interactive undo tree
,ss	Enable spell checking
,e	Open file prompt with current path
,<cr>	Clear search highlights
,r	Redraw screen
C-h	Move cursor to leftward pane
C-k	Move cursor to upward pane
C-j	Move cursor to downward pane
C-l	Move cursor to rightward pane (redraw is `,r` instead)
gq	Format selection using `hindent` for haskell buffers (`par` for others)
,y	Yank to OS clipboard
,d	Delete to OS clipboard
,p	Paste from OS clipboard

(If you prefer to restore the default screen redraw action of C-l then add unmap <c-l> to your vimrc.local)

Customizing

After installing this configuration, your .vimrc and .vim will be under version control. Don't alter these files. Instead, add your own settings to ~/.config/haskell-vim-now/vimrc.local.pre, ~/.config/haskell-vim-now/vimrc.local.

Adding Vim Plugins

Haskell-Vim-Now uses vim-plug to install plugins. It uses the following vim configuration structure to determine what to install:

call plug#begin('~/.vim/plugged')

" The plugins are named in github short form, for example:
Plug 'junegunn/vim-easy-align'

" All plug statements must be between plug#begin and plug#end
call plug#end()

However the .vimrc file in Haskell-Vim-Now is under version control so you shouldn't edit it directly. To add a plugin what you should do is add Plug statements to ~/.config/haskell-vim-now/plugins.vim. When ready reload .vimrc and run :PlugInstall to install plugins.

Neovim support

The .vimrc configuration is fully compatible with Neovim, and adds a few Neovim specific mappings for the terminal mode (terminal emulation is activated with :terminal). The mappings make Esc and c-[hjkl] function as one would expect them to from normal mode.

The Neovim configuration is found at .config/nvim, and is symlinked just like regular vim, which means you should only add your own settings to ~/.config/haskell-vim-now/vimrc.local.pre, ~/.config/haskell-vim-now/vimrc.local and ~/.config/haskell-vim-now/plugins.vim.

You can quickly backup and replace your Neovim setup by running the scripts/neovim.sh script.

Docker image

If you are into developing with Docker, you can use the image.

docker pull haskell:7.8
docker build -t haskell-vim .
docker run --rm -i -t haskell-vim /bin/bash

If instead you want to extract the vim setup from the image that is easy enough

docker build -t haskell-vim .
mkdir ~/.haskell-vim-now
cd ~/.haskell-vim-now
docker run --rm haskell-vim tar -cz -C /root/.haskell-vim-now . > haskell-vim-now.tgz
tar -xzf haskell-vim-now.tgz

However, some things (for example the hoogle database) use absolute paths and don't work correctly.

Advanced install methods

Basic install

In case you want to skip the haskell specific components and want to install just the common vim config you can use:

bash <(curl -sL https://git.io/haskell-vim-now) --basic

Installing from a fork or clone

If you have a modified fork you can use the --repo option to tell the install script the location of your repository:

bash <(curl -sL INSTALL-SCRIPT-URL) --repo FORK-URL

For example:

bash <(curl -sL https://raw.githubusercontent.com/begriffs/haskell-vim-now/master/install.sh) --repo https://github.com/begriffs/haskell-vim-now

If you have a local git clone you can use install.sh directly to install from your clone:

install.sh --repo CLONE-PATH

Troubleshooting

See this wiki page for tips on fixing installation problems.

Thank you!

Big thanks to contributors. I'd especially like to thank @SX91 for rewriting the installer and for other major improvements.