+ (format stream "~@<~S fell through ~S expression. ~
+ ~:_Wanted one of ~:S.~:>"
+ (type-error-datum condition)
+ (case-failure-name condition)
+ (case-failure-possibilities condition)))))
+
+(define-condition compiled-program-error (program-error)
+ ((message :initarg :message :reader program-error-message)
+ (source :initarg :source :reader program-error-source))
+ (:report (lambda (condition stream)
+ (format stream "Execution of a form compiled with errors.~%~
+ Form:~% ~A~%~
+ Compile-time error:~% ~A"
+ (program-error-source condition)
+ (program-error-message condition)))))
+
+(define-condition interpreted-program-error
+ (program-error encapsulated-condition)
+ ;; Unlike COMPILED-PROGRAM-ERROR, we don't need to dump these, so
+ ;; storing the original condition and form is OK.
+ ((form :initarg :form :reader program-error-form))
+ (:report (lambda (condition stream)
+ (format stream "~&Evaluation of~% ~S~%~
+ caused error:~% ~A~%"
+ (program-error-form condition)
+ (encapsulated-condition condition)))))
+
+(define-condition simple-control-error (simple-condition control-error) ())
+(define-condition simple-file-error (simple-condition file-error) ())
+(define-condition simple-program-error (simple-condition program-error) ())
+(define-condition simple-stream-error (simple-condition stream-error) ())
+(define-condition simple-parse-error (simple-condition parse-error) ())
+
+(define-condition character-coding-error (error)
+ ((external-format :initarg :external-format :reader character-coding-error-external-format)))
+(define-condition character-encoding-error (character-coding-error)
+ ((code :initarg :code :reader character-encoding-error-code)))
+(define-condition character-decoding-error (character-coding-error)
+ ((octets :initarg :octets :reader character-decoding-error-octets)))
+(define-condition stream-encoding-error (stream-error character-encoding-error)
+ ()
+ (:report
+ (lambda (c s)
+ (let ((stream (stream-error-stream c))
+ (code (character-encoding-error-code c)))
+ (format s "~@<encoding error on stream ~S (~S ~S): ~2I~_~
+ the character with code ~D cannot be encoded.~@:>"
+ stream ':external-format
+ (character-coding-error-external-format c)
+ code)))))
+(define-condition stream-decoding-error (stream-error character-decoding-error)
+ ()
+ (:report
+ (lambda (c s)
+ (let ((stream (stream-error-stream c))
+ (octets (character-decoding-error-octets c)))
+ (format s "~@<decoding error on stream ~S (~S ~S): ~2I~_~
+ the octet sequence ~S cannot be decoded.~@:>"
+ stream ':external-format
+ (character-coding-error-external-format c)
+ octets)))))
+
+(define-condition c-string-encoding-error (character-encoding-error)
+ ()
+ (:report
+ (lambda (c s)
+ (format s "~@<c-string encoding error (:external-format ~S): ~2I~_~
+ the character with code ~D cannot be encoded.~@:>"
+ (character-coding-error-external-format c)
+ (character-encoding-error-code c)))))