Function: 1+

1+ is a function defined in data.c.

Signature

(1+ NUMBER)

Documentation

Return NUMBER plus one. NUMBER may be a number or a marker.

Markers are converted to integers.

Other relevant functions are documented in the number group.

View in manual

Probably introduced at or before Emacs version 1.12.

Shortdoc

;; number
(1+ 2)
    => 3
  (let ((x 2)) (1+ x) x)
    => 2

Source Code

// Defined in /usr/src/emacs/src/data.c
{
  number = check_number_coerce_marker (number);

  if (FIXNUMP (number))
    return make_int (XFIXNUM (number) + 1);
  if (FLOATP (number))
    return (make_float (1.0 + XFLOAT_DATA (number)));
  mpz_add_ui (mpz[0], *xbignum_val (number), 1);
  return make_integer_mpz ();
}