How to get varargs as a string?

Question

Say I have a function that takes multiple arguments, how would I pass them as a single string argument to another function?

function test(...)
    " vimgrep is just an example
    vimgrep a:000 /some/path/**/*.txt
endfunction

When bound to a key, eg

command! -nargs=+ FIND call SimpleGrep(<args>)
nnoremap <M-f> :FIND<SPACE>

I get the error that the input is an unknown variable, using string(a:000) doesn't fix things.

How would a:000 be converted into a string so FIND a b c could be evaluated as if FIND "a b c" had been written?

Answer 1

Join the arguments together with join().

function test(...)
    " vimgrep is just an example
    execute 'vimgrep /'.join(a:000).'/ /some/path/**/*.txt'
endfunction
command! -nargs=+ FIND call SimpleGrep(<f-args>)
nnoremap <M-f> :FIND<SPACE>

Note: join() will join together with a single space and <f-args> will ignore extra spaces, so :FIND a b c is equivalent to :FIND a b c

For more help see:

:h join()
:h <f-args>
:h a:000