improve action funcref handling

Use dict key to reference instead of wrapping in funcref. This allow
nnn#action to take vimL lambdas and lua functions

autoload/nnn.vim

@@ -16,8 +16,8 @@ function! s:statusline()
     setlocal statusline=%#StatusLineTerm#\ nnn\ %#StatusLineTermNC#
 endfunction
 
-function! nnn#select_action(action) abort
-    let s:action = a:action
+function! nnn#select_action(key) abort
+    let s:action = g:nnn#action[a:key]
     " quit nnn
     if has('nvim')
         call feedkeys("i\<cr>")
@@ -78,7 +78,7 @@ function! s:eval_temp_file(opts)
     endif
 
     " Action passed is function
-    if (type(l:Cmd) == 2)
+    if (type(l:Cmd) == v:t_func)
         call l:Cmd(l:names)
     else
         " Edit the first item.

ftplugin/nnn.vim

@@ -4,11 +4,7 @@ endif
 let b:nnn_ftplugin = 1
 
 for key in keys(g:nnn#action)
-    if type(g:nnn#action[key]) == v:t_func
-        exec 'tnoremap <nowait><buffer><silent> '.key.' <c-\><c-n>:<c-u>call nnn#select_action('.string(g:nnn#action[key]).')<cr>'
-    else
-        exec 'tnoremap <nowait><buffer><silent> '.key.' <c-\><c-n>:<c-u>call nnn#select_action("'.g:nnn#action[key].'")<cr>'
-    endif
+    exec 'tnoremap <nowait><buffer><silent> '.key.' <cmd>call nnn#select_action("'.substitute(key, '<', '<lt>', 'g').'")<cr>'
 endfor
 
 setlocal nospell bufhidden=wipe nobuflisted nonumber