SETF expansions for NTH and AREF.

diff --git a/src/array.lisp b/src/array.lisp
index b66d87c..db7ad21 100644 (file)
--- a/src/array.lisp
+++ b/src/array.lisp
@@ -73,6 +73,16 @@
     (error "~S is not an array." array))  
   (storage-vector-set array index value))
 
+(define-setf-expander aref (array index)
+  (let ((g!array (gensym))
+        (g!index (gensym))
+        (g!value (gensym)))
+    (values (list g!array g!index)
+            (list array index)
+            (list g!value)
+            `(aset ,g!array ,g!index ,g!value)
+            `(aref ,g!array ,g!index))))
+
 
 ;;; Vectors
 

diff --git a/src/list.lisp b/src/list.lisp
index d39a6e6..6b58aae 100644 (file)
--- a/src/list.lisp
+++ b/src/list.lisp
@@ -68,6 +68,16 @@
 (defun nth (n list)
   (car (nthcdr n list)))
 
+(define-setf-expander nth (n list)
+  (let ((g!list (gensym))
+        (g!index (gensym))
+        (g!value (gensym)))
+    (values (list g!list g!index)
+            (list list n)
+            (list g!value)
+            `(rplaca (nthcdr ,g!index ,g!list) ,g!value)
+            `(nth ,g!index ,g!list))))
+
 (defun caar (x) (car (car x)))
 (defun cadr (x) (car (cdr x)))
 (defun cdar (x) (cdr (car x)))