+(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)))))
+
+(define-condition c-string-decoding-error (character-decoding-error)
+ ()
+ (:report
+ (lambda (c s)
+ (format s "~@<c-string decoding error (:external-format ~S): ~2I~_~
+ the octet sequence ~S cannot be decoded.~@:>"
+ (character-coding-error-external-format c)
+ (character-decoding-error-octets c)))))
+