a value to use instead (on an ongoing basis).

The store-value restart is generally used by handlers trying to recover from errors of types such as cell-error or type-error, which may wish to supply a replacement datum to be stored permanently.

(defun type-error-auto-coerce (c)
  (when (typep c 'type-error)
    (let ((r (find-restart 'store-value c)))
      (handler-case
          (let ((v (coerce (type-error-datum c) (type-error-expected-type c))))
            (invoke-restart r v))
        (error ()))))) 

→

TYPE-ERROR-AUTO-COERCE



(let ((x 3))
  (handler-bind ((type-error #'type-error-auto-coerce))
    (check-type x float) x))

→

3.0

{\secref\Restarts}, {\secref\InterfacesToRestarts}, Function INVOKE-RESTART, Function STORE-VALUE, Macro CCASE, Macro CHECK-TYPE, Macro CTYPECASE, Function USE-VALUE, Restart USE-VALUE