Calling hjkl keys from vim's command line

Question

Whenever I am browsing folded code in vim and press the l key I want it to open that fold recursively. For that I did the following: nmap l lzO. Which worked ok, apart from the fact of getting a E490: No fold found whenever I would press l not in a fold. I used that an excuse to learn about Vimscript and write a function for that and avoid the error.

Now, I am missing the part of how can I call a vim command like l or lzO from inside a function?

function! OpenFoldOrNot()
    if foldclosed(line(".")) == -1
        echo "just l"
        l # TODO
    else
        echo "open fold"
        lzO # TODO
    endif
endfunction

nmap l :call OpenFoldOrNot()<CR>

Answer 1

Try the normal command. For this case you will need normal! to avoid recursive execution of your function.

Answer 2

You could try the following, using the normal command (my vimscript is very rusty):

function! OpenFoldOrNot()
    if foldclosed(line(".")) == -1
        normal! l
    else
        normal! lzO
    endif
endfunction

nmap l :call OpenFoldOrNot()<CR>

Answer 3

Alternatively you can use a map-expression to make this kind of job easier.

nnoremap <expr> l foldclosed(line(".")) == -1 ? 'l' : 'lzO'

In a map expression the right hand side, {rhs}, of the mapping is a VimScript expression. This is evaluated to obtain what to execute. In your case it is used to determine if the mapping calls l or lz0.

For more help see:

:h :map-expression