express.vim

function! s:express(type)
	let expression = input('=', '', 'expression')
	let a_reg = @a
	let selection = &selection
	set selection=inclusive
	let selectcmd = "`[v`]"
	if a:type == 'line'
		let selectcmd = "'[V']"
	endif
	execute 'normal!'.selectcmd.'"ay'
	let @a = map([@a], expression)[0]
	execute 'normal! '.selectcmd.'"ap'
	silent! call repeat#set("\<Plug>(ExpressRepeat)".expression."\<CR>")
	let &selection = selection
	let @a = a_reg
endfunction

nnoremap <silent> <Plug>(ExpressRepeat) .
nnoremap <silent> <Plug>(Express) :<C-U>set operatorfunc=<SID>express<CR>g@
nmap c= <Plug>(Express)