vim-languages

This is a very simple plugin that generates Vim commands to add or remove the extension pragmas. Different GHC versions support different extensions, so the output of

$ ghc --supported-languages

is used to determine what commands to generate. It should be fairly robust: --supported-languages switch exists since at least GHC 7.6. The plugin supports pathogen, so to install it just run:

mkdir -p ~/.vim/bundle && cd ~/.vim/bundle && git clone git@github.com:supki/vim-languages

By default, the commands for the following extensions are generated:

• NoImplicitPrelude, NoMonomorphismRestriction
• Any extension that does not have No prefix but Rank2Types and NPlusKPatterns

The command name is the name of the extension, so

:RankNTypes

will add

{-# LANGUAGE RankNTypes #-}

Another call to :RankNTypes will remove the pragma.

The list of commands to generate is customizable:

• Add let g:vim_languages_exclude = ['Rank2Types', 'NPlusKPatterns', ...] line to your ~/.vimrc to exclude more commands from being generated

• Add let g:vim_languages_include = ['NoImplicitPrelude', 'NoMonomorphismRestriction] line to your ~/.vimrc to generate more commands

• Inclusion has a higher precedence

Note that the plugin expects the file to have all LANGUAGE pragmas as one big block at the top; it tolerates the single line comment syntax and pre-processor instructions but nothing else (e.g. OPTIONS_GHC pragmas interspersed in the list of LANGUAGE pragmas will break everything)