[functional-tests] from-to loop macro

functional-tests/loops.scm

@@ -1,6 +1,6 @@
 (library
   (loops)
-  (export upto while)
+  (export upto from-to while)
   (import (rnrs))
 
   (define-syntax upto
@@ -11,6 +11,14 @@
              (begin body ...)
              (loop (+ 1 var)))))))
 
+  (define-syntax from-to
+    (syntax-rules ()
+      ((_ (var f t step) b1 b2 ...)
+       (let loop ((var f))
+        (unless (= var t)
+                b1 b2 ...
+                (loop (+ var step)))))))
+
   (define-syntax while
     (syntax-rules ()
       ((_ (var exp) body ...)