Add CHAR=, EQL, NTHCDR, LAST, and NTH.

2 files changed, 32 insertions, 2 deletions

diff --git a/list-functions-2.lisp b/list-functions-2.lisp
index caa5a58..57e3976 100644
--- a/list-functions-2.lisp
+++ b/list-functions-2.lisp
@@ -20,7 +20,7 @@
 
 (export '(copy-tree assoc assoc-if assoc-if-not rassoc rassoc-if
           rassoc-if-not sublis nsublis mapcar mapcan mapcon acons
-          reverse nreverse maplist))
+          reverse nreverse maplist nthcdr last nth))
 
 
 (defun copy-tree (tree)
@@ -128,7 +128,25 @@
       (sys::cons (sys::car objects) (sys::cdr objects))
       nil))
 
+(defun dotted-length (list)
+  (if (consp list)
+      (1+ (dotted-length (cdr list)))
+      0))
+
 (defun length (list)
   (if list
       (%1+ (length (cdr list)))
       0))
+
+(defun last (list &optional (n 1))
+  (let ((l (dotted-length list)))
+    (nthcdr (- l n))))
+
+(defun nthcdr (n list)
+  (check-type n (integer 0))
+  (if (zerop n)
+      list
+      (nthcdr (1- n) (cdr list))))
+
+(defun nth (n list)
+  (car (nthcdr n list)))
diff --git a/types.lisp b/types.lisp
index c1bf8c7..e99c188 100644
--- a/types.lisp
+++ b/types.lisp
@@ -26,7 +26,7 @@
           array simple-array simple-vector simple-string
           simple-bit-vector sequence two-way-stream stream echo-stream
           broadcast-stream file-stream synonym-stream string-stream
-          concatenated-stream deftype typecase etypecase))
+          concatenated-stream deftype typecase etypecase char= eql))
 
 
 (setq *subtype-supertypes-dict*
@@ -200,3 +200,15 @@
   `(typecase ,expression
      ,@cases
      (otherwise (error "~A fell through ETYPECASE expression" expression))))
+
+
+(defun char= (x y)
+  (send-by-name x "isEqual:" y))
+
+(defun eql (x y)
+  (typecase x
+    (number (and (numberp y)
+                 (= x y))
+    (character (and (characterp y)
+                    (char= x y)))
+    (t (eq x y)))))