Convert javascript to coffeescript (ideal for jasmine specs)

gistfile1.vim

" convert javascript to coffeescript
 
command! ConvertJs :call ConvertJs()
 
function! ConvertJs()
  :norm =G
  :silent :%s/;$//e
  :silent :%s/var //ge
  :silent :g/^\s\+})$/d
  :silent :%s/function() {/->/ge
  :silent :%s/^\(\s\+\)\(\w\+\)$/\1\2 = null/e
  :silent :%s/function(\(\w\+\)) {/(\1) ->/ge
  :silent :%s/\/\//#/ge
  :silent :%s/beforeEach(->/beforeEach ->/e
  :silent :g/^})$/d
  :silent :%s/describe(/describe /ge
  :silent :%s/it(/it /ge
  :silent :%s/this\./@/ge
endfunction