0.9.4.77:

[sbcl.git] / doc / manual / beyond-ansi.texinfo

diff --git a/doc/manual/beyond-ansi.texinfo b/doc/manual/beyond-ansi.texinfo
index 2cde567..c79ee95 100644 (file)
--- a/doc/manual/beyond-ansi.texinfo
+++ b/doc/manual/beyond-ansi.texinfo
@@ -48,6 +48,7 @@ are:
 @findex compute-effective-method
 @findex sb-mop:compute-effective-method
 @code{compute-effective-method} only returns one value, not two.
 @findex compute-effective-method
 @findex sb-mop:compute-effective-method
 @code{compute-effective-method} only returns one value, not two.

+

 There is no record of what the second return value was meant to
 indicate, and apparently no clients for it.
   
 There is no record of what the second return value was meant to
 indicate, and apparently no clients for it.
   

@@ -60,6 +61,10 @@ the arguments @code{:declare} and @code{:declarations} to
 argument defining the declarations to be stored and returned by
 @code{generic-function-declarations}.
 
 argument defining the declarations to be stored and returned by
 @code{generic-function-declarations}.
 

+Where AMOP specifies @code{:declarations} as the keyword argument to
+@code{ensure-generic-function}, the Common Lisp standard specifies
+@code{:declare}.  Portable code should use @code{:declare}.
+

 @item
 @findex validate-superclass
 @findex finalize-inheritance
 @item
 @findex validate-superclass
 @findex finalize-inheritance

@@ -69,6 +74,8 @@ argument defining the declarations to be stored and returned by
 @tindex funcallable-standard-class
 @tindex sb-mop:funcallable-standard-class
 @tindex function
 @tindex funcallable-standard-class
 @tindex sb-mop:funcallable-standard-class
 @tindex function

+@findex sb-mop:class-prototype
+@findex class-prototype

 although SBCL obeys the requirement in AMOP for
 @code{validate-superclass} for @code{standard-class} and
 @code{funcallable-standard-class} to be compatible metaclasses, we
 although SBCL obeys the requirement in AMOP for
 @code{validate-superclass} for @code{standard-class} and
 @code{funcallable-standard-class} to be compatible metaclasses, we

@@ -77,6 +84,40 @@ of metaclass @code{funcallable-standard-class} must have
 @code{function} in its superclasses, and a class of metaclass
 @code{standard-class} must not.
 
 @code{function} in its superclasses, and a class of metaclass
 @code{standard-class} must not.
 

+@findex typep
+@findex class-of
+@findex subtypep
+At class finalization, a class prototype which is accessible by a
+standard mop function @code{sb-mop:class-prototype}.  The user can
+then ask whether this object is a @code{function} or not in several
+different ways: whether it is a function according to @code{typep};
+whether its @code{class-of} is @code{subtypep} @code{function}, or
+whether @code{function} appears in the superclasses of the class.  The
+additional consistency requirement comes from the desire to make all
+of these answers the same.
+
+The following class definitions are bad, and will lead to errors
+either immediately or if an instance is created:
+@lisp
+(defclass bad-object (funcallable-standard-object)
+  ()
+  (:metaclass standard-class))
+@end lisp
+@lisp
+(defclass bad-funcallable-object (standard-object)
+  ()
+  (:metaclass funcallable-standard-class))
+@end lisp
+The following definition is acceptable:
+@lisp
+(defclass mixin ()
+  ((slot :initarg slot)))
+(defclass funcallable-object (funcallable-standard-object mixin)
+  ()
+  (:metaclass funcallable-standard-class))
+@end lisp
+and leads to a class whose instances are funcallable and have one slot.
+

 @end itemize
 
 @node  Support For Unix
 @end itemize
 
 @node  Support For Unix