Int#downto

js/js.tests/test/org/jetbrains/k2js/test/semantics/RangeTest.java

@@ -48,4 +48,8 @@ public final class RangeTest extends SingleFileTranslationTest {
     public void testIntUpTo() throws Exception {
         fooBoxTest();
     }
+
+    public void testIntDownTo() throws Exception {
+        fooBoxTest();
+    }
 }

js/js.translator/src/org/jetbrains/k2js/translate/intrinsic/functions/factories/RangesFIF.java

@@ -31,5 +31,6 @@ public final class RangesFIF extends CompositeFIF {
 
     private RangesFIF() {
         add(pattern("Int.upto"), new CallStandardMethodIntrinsic("Kotlin.intUpto", true, 1));
+        add(pattern("Int.downto"), new CallStandardMethodIntrinsic("Kotlin.intDownto", true, 1));
     }
 }

js/js.translator/testFiles/kotlin_lib.js

@@ -43,7 +43,11 @@ var kotlin = {set:function (receiver, key, value) {
     };
 
     Kotlin.intUpto = function (from, limit) {
-        return Kotlin.$new(Kotlin.NumberRange)(from, limit - from + 1);
+        return Kotlin.$new(Kotlin.NumberRange)(from, limit - from + 1, false);
+    };
+
+    Kotlin.intDownto = function (from, limit) {
+        return Kotlin.$new(Kotlin.NumberRange)(from, from - limit + 1, true);
     };
 
     Kotlin.modules = {};

js/js.translator/testFiles/range/cases/intDownTo.kt

@@ -0,0 +1,11 @@
+package foo
+
+import java.util.ArrayList
+
+fun box() : Boolean {
+    var elems = ArrayList<Int>()
+    for (i in 4 downto 0) {
+      elems.add(i)
+    }
+    return elems[0] == 4 && elems[1] == 3 && elems[2] == 2 && elems[3] == 1 &&  elems[4] == 0
+}