|place||a place with list|
|key||keying value, also know as indicator|
|default||answer when key-value pair is not found, default is NIL|
GETF function searches supplied plist for value with matching key. Plist is list of even number of items. Each item pair specifies key and value. I.e. (K1 V1 K2 V2 ...). Return value is either value for first matching key, or specified default. Keys are matched by EQ function, therefore only suitable values are symbols and integers in range between MOST-NEGATIVE-FIXNUM and MOST-POSITIVE-FIXNUM constants. See also SETF, ASSOC and FIND.
(getf '(a b 4 d a x) 'a) => B (getf '(a b 4 d a x) 'x) => NIL (getf '(a b 4 d a x) 'x 'not-found) => NOT-FOUND (getf '(a b 4 d a x) 4 'not-found) => D