destructuring-bind

(destructuring-bind pattern form body...)

Binds the variables of pattern to the corresponding parts of the value of form and evaluates the body. The pattern is a macro-style lambda list: patterns nest in required positions, and &optional (with defaults and supplied-p), &rest/&body, &key (with defaults and supplied-p), and &aux are supported -- also inside nested patterns. &whole and &environment are not supported. Matching is lenient: a missing position binds to nil and surplus elements are ignored (no mismatch error); only an undeclared keyword under &key signals, unless &allow-other-keys is given.