X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Fcas.lisp;h=72e5800803fa983974c9235723a66427c8e0752d;hb=bcd323c39d6f5f80020ba4a5d9eb8d348c6cc499;hp=04f6aa24ff4980433b7d5239c2607a630c07b91c;hpb=27f48073d85c9c56df88fb3d5e47055b8a471b73;p=sbcl.git

diff --git a/src/code/cas.lisp b/src/code/cas.lisp
index 04f6aa2..72e5800 100644
--- a/src/code/cas.lisp
+++ b/src/code/cas.lisp
@@ -80,9 +80,9 @@ Example:
           ,new))))
 
 EXPERIMENTAL: Interface subject to change."
-  (flet ((invalid-place ()
-           (error "Invalid place to CAS: ~S" place)))
     (let ((expanded (sb!xc:macroexpand place environment)))
+      (flet ((invalid-place ()
+           (error "Invalid place to CAS: ~S -> ~S" place expanded)))
       (unless (consp expanded)
         ;; FIXME: Allow (CAS *FOO* <OLD> <NEW>), maybe?
         (invalid-place))
@@ -93,7 +93,7 @@ EXPERIMENTAL: Interface subject to change."
           (cond
             ;; CAS expander.
             (info
-             (funcall info place environment))
+             (funcall info expanded environment))
 
             ;; Structure accessor
             ((setf info (info :function :structure-accessor name))
@@ -207,7 +207,8 @@ EXPERIMENTAL: Interface subject to change."
 Two values are considered to match if they are EQ. Returns the previous value
 of PLACE: if the returned value is EQ to OLD, the swap was carried out.
 
-PLACE must be an accessor form whose CAR is one of the following:
+PLACE must be an CAS-able place. Built-in CAS-able places are accessor forms
+whose CAR is one of the following:
 
  CAR, CDR, FIRST, REST, SVREF, SYMBOL-PLIST, SYMBOL-VALUE, SVREF, SLOT-VALUE
  SB-MOP:STANDARD-INSTANCE-ACCESS, SB-MOP:FUNCALLABLE-STANDARD-INSTANCE-ACCESS,
@@ -218,13 +219,15 @@ other then FIXNUM or T.
 
 In case of SLOT-VALUE, if the slot is unbound, SLOT-UNBOUND is called unless
 OLD is EQ to SB-PCL:+SLOT-UNBOUND+ in which case SB-PCL:+SLOT-UNBOUND+ is
-returned and NEW is assigned to the slot.
-
-Additionally, the results are unspecified if there is an applicable method on
-either SB-MOP:SLOT-VALUE-USING-CLASS, (SETF SB-MOP:SLOT-VALUE-USING-CLASS), or
+returned and NEW is assigned to the slot. Additionally, the results are
+unspecified if there is an applicable method on either
+SB-MOP:SLOT-VALUE-USING-CLASS, (SETF SB-MOP:SLOT-VALUE-USING-CLASS), or
 SB-MOP:SLOT-BOUNDP-USING-CLASS.
 
-EXPERIMENTAL: Interface subject to change."
+Additionally, the PLACE can be a anything for which a CAS-expansion has been
+specified using DEFCAS, DEFINE-CAS-EXPANDER, or for which a CAS-function has
+been defined. (See SB-EXT:CAS for more information.)
+"
   `(cas ,place ,old ,new))
 
 ;;; Out-of-line definitions for various primitive cas functions.