Add useful "map combinations" macro. See counter example

examples/simple-counter/simple_counter_tb.utest

@@ -1,26 +1,8 @@
 ;; -*- scheme -*-
 
-;;; Make lists combinations
-;;; Example: (combinations '(1 2 3) '(a b)) -> '((1 a) (1 b) (2 a) (2 b) (3 a) (3 b))
-(define (combinations . lists)
-  (cond
-   ((null? lists) '())
-   ((null? (cdr lists)) (car lists))
-   (else
-    (fold (lambda (comb out)
-            (append out
-                    (map (lambda (x)
-                           (if (list? comb)
-                               (cons x comb)
-                               (list x comb)))
-                         (car lists))))
-          '() (apply combinations (cdr lists))))))
-
 ;;; Testbenches
-(map
- (lambda (l)
-   (let ((count (car l))
-         (direction (cadr l)))
+(utest/map-comb
+ (count direction)
  (utest/tb
       ((format "c~a_d~a" count direction)
        "More complex testbench for Simple Counter"
@@ -35,10 +17,8 @@
        "simple_counter_tb"
        #:parameters `((COUNT      ,count)
                       (ITERATIONS ,(* count 3))
-                      (DIRECTION  ,direction))))))
-
- (combinations
+                      (DIRECTION  ,direction))))
  (append '(10 100 1000 16 64 256)
           (let ((state (seed->random-state 0)))
             (map (lambda (x) (+ 2 (random 200 state))) (iota 100))))
-  '(1 -1 0)))
+ '(1 -1 0))

utest.scm

@@ -967,6 +967,18 @@
     ((_ () body ...)
      (utest/tb (#f) body ...))))
 
+;;;
+;;; Map combinations macro
+;;;
+(define-syntax utest/map-comb
+  (syntax-rules ()
+    ((_ (args ...) (body ...) lists ...)
+     (apply
+      map
+      (lambda (args ...) (body ...))
+      (transpose
+       (combinations lists ...))))))
+
 ;;;
 ;;; Delete working folders
 ;;;