src/: Factor out common machinery in `check-method-type' methods.

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

diff --git a/src/class-make-impl.lisp b/src/class-make-impl.lisp
index aef694863378ac5889064ab626d3a855e7cb8abf..ed6189f982ae27e2862e054e8d9875facf02de48 100644 (file)
--- a/src/class-make-impl.lisp
+++ b/src/class-make-impl.lisp
@@ -28,24 +28,6 @@ (cl:in-package #:sod)
 ;;;--------------------------------------------------------------------------
 ;;; Classes.
 
-(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."
-  (maximum (mapcar #'sod-class-metaclass
-                  (sod-class-direct-superclasses class))
-          #'sod-subclass-p
-          (format nil "metaclass for `~A'" class)))
-
 (defmethod shared-initialize :after ((class sod-class) slot-names &key pset)
   "Specific behaviour for SOD class initialization.
 
@@ -67,11 +49,11 @@   (default-slot-from-property (class 'nickname slot-names)
       (pset :nick :id)
     (string-downcase (slot-value class 'name)))
 
-  ;; If no metaclass, guess one in a (Lisp) class-specific way.
+  ;; Set the metaclass if the appropriate property has been provided;
+  ;; otherwise leave it unbound for now, and we'll sort out the mess during
+  ;; finalization.
   (default-slot-from-property (class 'metaclass slot-names)
-      (pset :metaclass :id meta (find-sod-class meta))
-    (and (sod-class-direct-superclasses class)
-        (guess-metaclass class)))
+      (pset :metaclass :id meta (find-sod-class meta)))
 
   ;; If no chain-link, then start a new chain here.
   (default-slot-from-property (class 'chain-link slot-names)
@@ -239,15 +221,38 @@ (defmethod check-method-type
     ((method sod-method) (message sod-message) (type c-type))
   (error "Methods must have function type, not ~A" type))
 
+(export 'check-method-return-type)
+(defun check-method-return-type (method-type wanted-type)
+  "Signal an error unless METHOD-TYPE does not return the WANTED-TYPE."
+  (let ((method-returns (c-type-subtype method-type)))
+    (unless (c-type-equal-p method-returns wanted-type)
+      (error "Method return type ~A should be ~A"
+            method-returns wanted-type))))
+
+(export 'check-method-return-type-against-message)
+(defun check-method-return-type-against-message (method-type message-type)
+  "Signal an error unless METHOD-TYPE and MESSAGE-TYPE return the same type."
+  (let ((message-returns (c-type-subtype message-type))
+       (method-returns (c-type-subtype method-type)))
+    (unless (c-type-equal-p message-returns method-returns)
+      (error "Method return type ~A doesn't match message ~A"
+            method-returns message-returns))))
+
+(export 'check-method-argument-lists)
+(defun check-method-argument-lists (method-type message-type)
+  "Signal an error unless METHOD-TYPE and MESSAGE-TYPE have matching argument
+   lists.
+
+  This checks that the two types have matching lists of arguments."
+  (unless (argument-lists-compatible-p (c-function-arguments message-type)
+                                      (c-function-arguments method-type))
+    (error "Method arguments ~A don't match message ~A"
+          method-type message-type)))
+
 (defmethod check-method-type
     ((method sod-method) (message sod-message) (type c-function-type))
   (with-slots ((msgtype %type)) message
-    (unless (c-type-equal-p (c-type-subtype msgtype)
-                           (c-type-subtype type))
-      (error "Method return type ~A doesn't match message ~A"
-             (c-type-subtype msgtype) (c-type-subtype type)))
-    (unless (argument-lists-compatible-p (c-function-arguments msgtype)
-                                        (c-function-arguments type))
-      (error "Method arguments ~A don't match message ~A" type msgtype))))
+    (check-method-return-type-against-message type msgtype)
+    (check-method-argument-lists type msgtype)))
 
 ;;;----- That's all, folks --------------------------------------------------