X-Git-Url: https://git.distorted.org.uk/~mdw/sod/blobdiff_plain/284f1fa2ace3e276052ff1bd7d66442500e693da..4307347660f48628e307f299eb4fac58ba35fd1a:/src/class-make-impl.lisp

diff --git a/src/class-make-impl.lisp b/src/class-make-impl.lisp
index dba6965..5b8baf0 100644
--- a/src/class-make-impl.lisp
+++ b/src/class-make-impl.lisp
@@ -221,15 +221,47 @@
     ((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 (a) the two types have matching lists of mandatory
+  arguments, and (b) that either both or neither types accept keyword
+  arguments."
+  (let ((message-keywords-p (typep message-type 'c-keyword-function-type))
+	(method-keywords-p (typep method-type 'c-keyword-function-type)))
+    (cond (message-keywords-p
+	   (unless method-keywords-p
+	     (error "Method must declare a keyword argument list")))
+	  (method-keywords-p
+	   (error "Method must not declare a keyword argument list"))))
+  (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 --------------------------------------------------