elt (Accessor)

Syntax:

(setf (elt sequence index) new-object)

Arguments and Values:

sequence—a proper sequence.

index—a valid sequence index for sequence.

object—an object.

new-object—an object.

Description:

Accesses the element of sequence specified by index.

Examples:

 (setq str (copy-seq "0123456789")) → "0123456789"
 (elt str 6) → #\6
 (setf (elt str 0) #\#) → #\#
 str → "#123456789"

Exceptional Situations:

Should be prepared to signal an error of type type-error if sequence is not a proper sequence. Should signal an error of type type-error if index is not a valid sequence index for sequence.

See Also:

aref, nth, Section 3.2.1 (Compiler Terminology)

Notes:

aref may be used to access vector elements that are beyond the vector's fill pointer.