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
Section 9.1.4.2 (Restarts), Section 9.1.4.2.2 (Interfaces to Restarts), invoke-restart, store-value (function), ccase, check-type, ctypecase, use-value (function and restart)