Check out http://haskelllive.com/environment.html http://haskelllive.com/environment.html I don't use Syntastic, but haskellmode-vim and ghcmod-vim integrate n

Check out http://haskelllive.com/environment.html http://haskelllive.com/environment.html I don't use Syntastic, but haskellmode-vim and ghcmod-vim integrate nicely with ghci, and neco-ghc gives autocompletion. I don't use tags files or other project-level stuff, the above is good enough to get started. Also once you have ghcmod-vim you can map a key to tell you the type of an expression: au FileType haskell nnoremap <buffer> <F12> :GhcModType<CR> It does take some work to get all these things installed, however.