chore: more tests, fixes

- add DELAY
- fix definition of OF-MAX-LENGTH
- add ignorable declaration to CONJ and DISJ
- lots of new tests

lens.lisp

@@ -102,7 +102,7 @@
 
 (defun-ct of-max-length (len)
   (lambda (it)
-    (>= (length it)
+    (<= (length it)
         len)))
 
 (defun-ct applicable-when (fun test)
@@ -114,6 +114,7 @@
 (defmacro conj (&rest fns)
   (let ((dat (gensym "dat")))
     `(lambda (,dat)
+       (declare (ignorable ,dat))
        (and ,@(mapcar (lambda (fn)
                         `(funcall ,fn ,dat))
                       fns)))))
@@ -226,6 +227,13 @@
                        (apply f args))
                      r)))))
 
+(defun delay ()
+  "Return a function that always returns the last thing it was called with"
+  (let ((result nil))
+    (lambda (v)
+      (prog1 result
+        (setf result v)))))
+
 (defun =>> (fun1 fun2)
   (lambda (i)
     (prog1 (funcall fun1 i)