control-string—a format string; not evaluated.
function—a function.
Returns a function which has behavior equivalent to:
#'(lambda (*standard-output* &rest arguments) (apply #'format t control-string arguments) arguments-tail)
where arguments-tail is either the tail of arguments
which has as its car the argument that would be processed next
if there were more format directives in the control-string,
or else nil
if no more arguments follow the most recently
processed argument.
(funcall (formatter "~&~A~A") *standard-output* 'a 'b 'c) ▷ AB → (C) (format t (formatter "~&~A~A") 'a 'b 'c) ▷ AB → NIL
Might signal an error (at macro expansion time or at run time) if the argument is not a valid format string.