- (let (;; KMP idiom, using stream itself as EOF value
- (command (read *standard-input* nil *standard-input*)))
- (typecase command
- (stream ; i.e. EOF
+ (let* (;; newly-consed object for hermetic protection against
+ ;; mischievous input like #.*EOF-OBJECT*:
+ (eof (cons *eof-object* nil))
+ (command (read *standard-input* nil eof)))
+ (when (eq command eof)