X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/sod/blobdiff_plain/b2983f3591981a916f748362d91ff0e2817552cb..refs/heads/mdw/progfmt:/src/class-layout-proto.lisp

diff --git a/src/class-layout-proto.lisp b/src/class-layout-proto.lisp
index 927700f..5c755a3 100644
--- a/src/class-layout-proto.lisp
+++ b/src/class-layout-proto.lisp
@@ -68,6 +68,19 @@ (defgeneric compute-effective-slot (class slot)
    SLOT is a direct slot defined on CLASS or one of its superclasses.
    (Metaclass initializers are handled using a different mechanism.)"))
 
+(export 'find-class-initializer)
+(defgeneric find-class-initializer (slot class)
+  (:documentation
+   "Return an initializer value (any printable value) for a class slot SLOT.
+
+   The initializer might come either from the SLOT's defining class (which it
+   already knows), or from the instance CLASS, of which the defining class is
+   be (a superclass of) the metaclass.
+
+   This is used as part of `has-class-initializer-p' and the default output
+   hook for `effective-slot': if you override both of those then you don't
+   need to override this too."))
+
 ;;;--------------------------------------------------------------------------
 ;;; Instance layout.
 
@@ -266,6 +279,7 @@ (defclass chain-offset ()
    object's metadata; but that would either require a search or we'd have to
    be able work out the target chain's index in the table."))
 
+(export 'make-chain-offset)
 (defgeneric make-chain-offset (class chain-head target-head)
   (:documentation
    "Return the offset from CHAIN-HEAD to TARGET-HEAD."))