au BufRead,BufNewFile *.lexs set filetype=elixir "File extension used by https://github.com/mhanberg/temple
au BufRead,BufNewFile * call s:DetectElixir()

function! s:DetectElixir()
  if (!did_filetype() || &filetype !=# 'elixir') && getline(1) =~# '^#!.*\<elixir\>'
    set filetype=elixir
  endif
endfunction