[functional tests] more work on the binary-format macro

functional-tests/list-utils.scm

@@ -1,8 +1,13 @@
 (library
   (list-utils)
-  (export intersperse iterate accumulate)
+  (export tails intersperse iterate accumulate)
   (import (rnrs))
 
+  (define (tails xs)
+    (if (null? xs)
+        '()
+        (cons xs (tails (cdr xs)))))
+
   (define (intersperse sep xs)
     (cond
       ((null? xs) '())