- (let ((predicate-name (second hairy-spec)))
- (declare (type symbol predicate-name)) ; by ANSI spec of SATISFIES
- (if (fboundp predicate-name)
- (let* (;; "Is OBJ of the SATISFIES type?" represented
- ;; as a generalized boolean.
- ;;
- ;; (Why IGNORE-ERRORS? This code is used to try to
- ;; check type relationships at compile time.
- ;; Passing only-slightly-twisted types like
- ;; (AND INTEGER (SATISFIES ODDP)) into the
- ;; rather-significantly-twisted type dispatch
- ;; system can easily give rise to oddities like
- ;; calling predicates like ODDP on values they
- ;; don't like. (E.g. on OBJ=#\NEWLINE when the
- ;; above type is tested for TYPE= against
- ;; STANDARD-CHAR, represented as a
- ;; MEMBER-TYPE.) In such cases, NIL seems to be
- ;; an appropriate answer to "is OBJ of the
- ;; SATISFIES type?")
- (gbool (ignore-errors (funcall predicate-name obj)))
- ;; RAW coerced to a pure BOOLEAN value
- (bool (not (not gbool))))
- (values bool t))
- (values nil nil)))))))))
+ ;; If the SATISFIES function is not foldable, we cannot answer!
+ (let* ((form `(,(second hairy-spec) ',obj)))
+ (multiple-value-bind (ok result)
+ (sb!c::constant-function-call-p form nil nil)
+ (values (not (null result)) ok)))))))))