[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Is this a bug or not?

Hey fans,


(defclass meta1 (standard-class) ())

in one file, and compile and load this file.


(defclass my-metaclass (meta1)

(defclass my-class () () (:metaclass my-metaclass))

in another file (say meta-error.lisp), 
compiling this file leads to:

USER(395): (compile-file "meta-error.lisp")
; --- Compiling file /users/lothar/prokon/konwerk-obk/meta-error.lisp ---
; While compiling (:TOP-LEVEL-FORM "meta-error.lisp" 2):
Error: While computing the class precedence list of the class named META1.
The class named META1 is a forward referenced class.
The class named META1 is a direct superclass of the class named META1.
  [condition type: PROGRAM-ERROR]

Restart actions (select using :continue):
 0: retry the compilation of /users/lothar/prokon/konwerk-obk/meta-error.lisp
 1: continue compiling /users/lothar/prokon/konwerk-obk/meta-error.lisp but generate no output file

[changing package from "COMMON-LISP-USER" to "CLOS"]
[1] CLOS(396): 

Having all definitions in one file, 
or separating the definition of my-class in another file, 
or simply loading the file meta-error.lisp
lead to the desired behaviour (i.e. defining the classes without an error).

The problem might occure because meta1 is not known in the compiler
environment, there for a forward referenced class is created...?

Are there any other solutions as separating definitions in files?

Best wishes


 Lothar Hotz
 University of Hamburg               phone:          +49-40-4123-6536
 Departement of Computer Science     fax:            +49-40-4123-6530
 Bodenstedtstrasse 16                email: HOTZ@fbihh.informatik.uni-hamburg.de
 2000 Hamburg 50