Function: mapcan

mapcan is a function defined in fns.c.

Signature

(mapcan FUNCTION SEQUENCE)

Documentation

Apply FUNCTION to each element of SEQUENCE, and concatenate the results by altering them (using nconc). SEQUENCE may be a list, a vector, a bool-vector, or a string.

Other relevant functions are documented in the list group.

Probably introduced at or before Emacs version 26.1.

Shortdoc

;; list
(mapcan #'list '(1 2 3))
    => (1 2 3)

Source Code

// Defined in /usr/src/emacs/src/fns.c
{
  USE_SAFE_ALLOCA;
  EMACS_INT leni = XFIXNAT (Flength (sequence));
  if (CHAR_TABLE_P (sequence))
    wrong_type_argument (Qlistp, sequence);
  Lisp_Object *args;
  SAFE_ALLOCA_LISP (args, leni);
  ptrdiff_t nmapped = mapcar1 (leni, args, function, sequence);
  Lisp_Object ret = Fnconc (nmapped, args);
  SAFE_FREE ();
  return ret;
}