List abbreviation under cursor - vim

" List Abbreviations for word behind cursor
" Barry Arthur, Jan 04 2012

function! CursorWord()
  return matchstr(strpart(getline('.'), 0, col('.')), '\w\+\ze\s*$')
endfunction

function! AbbrList(word)
  exe "iabbr ".a:word
  return "\<c-w>".a:word
endfunction

inoremap <expr> <leader>a AbbrList(CursorWord())