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 // Setting a breakpoint in a generator function works, and we can

 // traverse the stack and evaluate expressions in the context of older

 // generator frames.

 var g = newGlobal();

 var dbg = Debugger(g);

 dbg.onDebuggerStatement = function (frame) {

     function hit(frame) {

         assertEq(frame.generator, true);

         assertEq(frame.older.generator, true);

         frame.older.eval("q += 16");

     }

     var s = frame.script;

     var offs = s.getLineOffsets(g.line0 + 9);

     for (var i = 0; i < offs.length; i++)

         s.setBreakpoint(offs[i], {hit: hit});

 };

 g.eval("line0 = Error().lineNumber;\n" +

        "function* g(x) {\n" +   // + 1

        "    var q = 10;\n" +    // + 2

        "    yield* x;\n" +      // + 3

        "    return q;\n" +      // + 4

        "}\n" +                  // + 5

        "function* range(n) {\n" + // + 6

        "    debugger;\n" +      // + 7

        "    for (var i = 0; i < n; i++)\n" + // + 8

        "        yield i;\n" +   // + 9  <-- breakpoint

        "    return;\n" + // so that line 9 only has the yield

        "}");

 g.eval("var iter = g(range(2))");

 g.eval("var first = iter.next().value");

 g.eval("var second = iter.next().value");

 g.eval("var third = iter.next().value");

 assertEq(g.first, 0);

 assertEq(g.second, 1);

 assertEq(g.third, 42);