diff --git a/lib/std.js b/lib/std.js
index 0bbfcf0..8365217 100644
--- a/lib/std.js
+++ b/lib/std.js
@@ -102,8 +102,11 @@ function sleep(ms, callback) {
 function repeat(target, callback, onError) {
     switch (typeof target) {
         case "number":
-		case "boolean":
+        case "boolean":
             var ms = target;
+
+            var i = 0;
+			var n = 0;
             var handler = null;
             var cur = Date.now();
             var end = cur + ms;
@@ -112,7 +115,10 @@ function repeat(target, callback, onError) {
                 while (ms === true ? true : (cur < end)) {
                     try {
                         if (typeof callback === "function")
-                            callback(cur)
+                            var n = callback(i);
+                            if (typeof n === "number")
+                                i += n
+                            ;
                         ;
                     } catch (e) {
                         if (typeof onError === "function")