au BufNewFile,BufRead *.i   set filetype=swig
au BufNewFile,BufRead *.swg set filetype=swig
au BufNewFile,BufRead *.g   set filetype=antlr3
au BufNewFile,BufRead *.g4  set filetype=antlr4
au BufNewFile,BufRead *.gv  set filetype=dot