VimでOCamlを書くためにmerlinとocp-indentを設定する ref: http://qiita.com/kmtr/items/25661e445278d6587de0

file0.txt

$ brew install ocaml --with-x11
$ brew install opam

file1.txt

$ opam install merlin
$ opam install ocp-indent

file2.txt

let g:opamshare = substitute(system('opam config var share'),'\n$','','''')
execute 'set rtp+=' . g:opamshare . '/merlin/vim'

file3.vim

NeoBundle 'scrooloose/syntastic'

file4.vim

let g:syntastic_ocaml_checkers = ['merlin']

file5.vim

execute 'set rtp^=' . g:opamshare . '/ocp-indent/vim'

file6.vim

function! s:ocaml_format()
    let now_line = line('.')
    exec ':%! ocp-indent'
    exec ':' . now_line
endfunction

augroup ocaml_format
    autocmd!
    autocmd BufWrite,FileWritePre,FileAppendPre *.mli\= call s:ocaml_format()
augroup END