Function: subr-arity

subr-arity is a function defined in data.c.

Signature

(subr-arity SUBR)

Documentation

Return minimum and maximum number of args allowed for SUBR.

SUBR must be a built-in function. The returned value is a pair (MIN . MAX). MIN is the minimum number of args. MAX is the maximum number or the symbol many, for a function with &rest args, or unevalled for a special form.

View in manual

Probably introduced at or before Emacs version 21.1.

Source Code

// Defined in /usr/src/emacs/src/data.c
{
  short minargs, maxargs;
  CHECK_SUBR (subr);
  minargs = XSUBR (subr)->min_args;
  maxargs = XSUBR (subr)->max_args;
  return Fcons (make_fixnum (minargs),
		maxargs == MANY ?        Qmany
		: maxargs == UNEVALLED ? Qunevalled
		:                        make_fixnum (maxargs));
}