This is a plugin to integrate cabal-fmt into your vim workflow. It will run cabal-fmt on Cabal buffers every time they are saved. It requires cabal-fmt be accessible from your $PATH.

First install cabal-fmt via Cabal, Stack or Nix:

$ stack install cabal-fmt --resolver=lts-15.10   # via stack
$ cabal new-install cabal-fmt --installdir=/home/user/.local/bin # via cabal
$ nix-build -A cabal-fmt   # via nix

If you are using pathogen.vim unpack this repository into your vim or neovim configuration directory.

$ cd ~/.vim/bundle         # for vim
$ cd ~/.config/nvim/bundle # for neovim
$ git clone https://github.com/sdiehl/vim-cabalfmt.git

If you are using Vundle add the following to your configuration file:

"Cabal Formatting
Plugin 'sdiehl/vim-cabalfmt'

If you are using vim-plug add the following to your configuration file:

"Cabal Formatting
Plug 'sdiehl/vim-cabalfmt'

The default settings will work fine out of the box without any aditional configuration.

If you have a non-standard $PATH then set g:cabalfmt_command Vim variable to the location of the cabal-fmt binary.

The specific flags for cabal-fmt can be configured by changing the Vim variable g:cabalfmt_options. For example to use two space indentation.

let g:cabalfmt_options=["--indent 2"]

If instead of formatting on save, you wish to bind formatting to a specific keypress add the following to your .vimrc or init.vim. For example to bind file formatting to the key sequence tf use:

nnoremap tf :call RunCabal()<CR>

To manually install the formatter on a specific file extension invoke RunCabal() as a BufWritePre hook.

autocmd BufWritePre *.cabal :call RunCabal()

MIT License Copyright (c) 2020, Stephen Diehl