doc/syntax.tex, src/sod-module.5: Typeset `<qualifier>s' properly.

[sod] / src / class-finalize-impl.lisp

diff --git a/src/class-finalize-impl.lisp b/src/class-finalize-impl.lisp
index b0e31ce1c8eabbdac55c5a16b0b9b9a43ca7a6fb..36d56e042ff5304760e94e8a7ef097966586c081 100644 (file)
--- a/src/class-finalize-impl.lisp
+++ b/src/class-finalize-impl.lisp
@@ -7,7 +7,7 @@
 
 ;;;----- Licensing notice ---------------------------------------------------
 ;;;
-;;; This file is part of the Sensble Object Design, an object system for C.
+;;; This file is part of the Sensible Object Design, an object system for C.
 ;;;
 ;;; SOD is free software; you can redistribute it and/or modify
 ;;; it under the terms of the GNU General Public License as published by
@@ -275,6 +275,35 @@ (defmethod compute-chains ((class sod-class))
                                           (gethash super table))
                                         (cdr class-precedence-list)))))))))
 
+;;;--------------------------------------------------------------------------
+;;; Metaclasses.
+
+(defun maximum (items order what)
+  "Return a maximum item according to the non-strict partial ORDER."
+  (reduce (lambda (best this)
+           (cond ((funcall order best this) best)
+                 ((funcall order this best) this)
+                 (t (error "Unable to choose best ~A." what))))
+         items))
+
+(defmethod guess-metaclass ((class sod-class))
+  "Default metaclass-guessing function for classes.
+
+   Return the most specific metaclass of any of the CLASS's direct
+   superclasses."
+
+  ;; During bootstrapping, our superclasses might not have their own
+  ;; metaclasses resolved yet.  If we find this, then throw `bootstrapping'
+  ;; so that `shared-initialize' on `sod-class' can catch it (or as a shot
+  ;; across the bows of anyone else who calls us).
+  (maximum (mapcar (lambda (super)
+                    (if (slot-boundp super 'metaclass)
+                        (slot-value super 'metaclass)
+                        (throw 'bootstrapping nil)))
+                  (sod-class-direct-superclasses class))
+          #'sod-subclass-p
+          (format nil "metaclass for `~A'" class)))
+
 ;;;--------------------------------------------------------------------------
 ;;; Sanity checking.
 
@@ -350,7 +379,12 @@ (defmethod finalize-sod-class ((class sod-class))
       ((nil)
 
        ;; If this fails, mark the class as a loss.
-       (setf (sod-class-state class) :broken)
+       (setf (slot-value class 'state) :broken)
+
+       ;; Set up the metaclass if it's not been set already.  This is delayed
+       ;; to give bootstrapping a chance to set up metaclass and superclass
+       ;; circularities.
+       (default-slot (class 'metaclass) (guess-metaclass class))
 
        ;; Finalize all of the superclasses.  There's some special pleading
        ;; here to make bootstrapping work: we don't try to finalize the
@@ -366,7 +400,7 @@ (defmethod finalize-sod-class ((class sod-class))
           (finalize-sod-class metaclass)))
 
        ;; Stash the class's type.
-       (setf (sod-class-type class)
+       (setf (slot-value class '%type)
             (make-class-type (sod-class-name class)))
 
        ;; Clobber the lists of items if they've not been set.
@@ -388,7 +422,7 @@ (defmethod finalize-sod-class ((class sod-class))
         (setf (values chain-head chain chains) (compute-chains class)))
 
        ;; Done.
-       (setf (sod-class-state class) :finalized)
+       (setf (slot-value class 'state) :finalized)
        t)
 
       (:broken
@@ -397,13 +431,13 @@ (defmethod finalize-sod-class ((class sod-class))
       (:finalized
        t))))
 
-(macrolet ((define-layout-slot (slot (class) &body body)
-            `(define-on-demand-slot sod-class ,slot (,class)
-               (check-class-is-finalized ,class)
-               ,@body)))
-  (flet ((check-class-is-finalized (class)
-          (unless (eq (sod-class-state class) :finalized)
-            (error "Class ~S is not finalized" class))))
+(flet ((check-class-is-finalized (class)
+        (unless (eq (sod-class-state class) :finalized)
+          (error "Class ~S is not finalized" class))))
+  (macrolet ((define-layout-slot (slot (class) &body body)
+              `(define-on-demand-slot sod-class ,slot (,class)
+                 (check-class-is-finalized ,class)
+                 ,@body)))
     (define-layout-slot %ilayout (class)
       (compute-ilayout class))
     (define-layout-slot effective-methods (class)