926685 - ForOfIterator comment is out of date

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Jason Orendorff [:jorendorff]]

The comment on ForOfIterator in jsiter.h says:

> * Convenience class for imitating a JS level for-of loop. Typical usage:
> *
> *     ForOfIterator it(cx);
> *     if (!it.init(iterable))
> *         return false;
> *     RootedValue val(cx);
> *     for (;;) {
> *        if (!next(&val, &done))
> *            return false;
> *        if (!DoStuff(cx, val))
> *            return false;
> *     }
> *

Unfortunately it is not that simple. Real usage is like this:

        ForOfIterator it(cx);
        if (!it.init(iterable))
            return false;
        RootedValue val(cx);
        bool done;
        for (;;) {
           if (!next(&val, &done))
               return false;
           if (done)
               break;
           if (!DoStuff(cx, val))
               return false;
        }

The comment should be fixed. Ideally the API could be streamlined:

        ForOfIterator it(cx);
        if (!it.first(iterable))
            return false;
        while (!it.done) {
            if (!DoStuff(cx, it.value))
                return false;
            if (!it.next())
                return false;
        }

Comment 1

[Boris Zbarsky [:bzbarsky]]

This got fixed in bug 952873.