Issue with compiler recognising a functional interface?

[Paul Sandoz]

Hi,

I am running into an issue with the compiler with latest code.

See end of email for all relevant interfaces.

The compiler fails for:

  IntInfiniteIterator iterator = () -> t; 

    [javac] /Users/sandoz/Projects/jdk8/lambda/jdk/src/share/classes/java/util/streams/primitives/Primitives.java:282: error: incompatible types: the target type must be a functional interface
    [javac]             IntInfiniteIterator iterator = () -> t;

But works for:

  InfiniteIterator<T> iterator = () -> t;

I would of expected the former to work since there is just one non-default method.

Paul.

interface Iterator<E> {
    boolean hasNext();

    E next();

    default void remove() {
        throw new UnsupportedOperationException("remove");
    }

    default void forEach(Block<? super E> block) {
        while (hasNext())
            block.apply(next());
    }
}

interface InfiniteIterator<T> extends Iterator<T> {
    @Override
    public default boolean hasNext() {
        return true;
    }
}

interface IntIterator extends Iterator<Integer> {

    // Iterator<Integer>

    @Override
    default Integer next() {
        Logger.getLogger(getClass().getName()).log(Level.WARNING, "{0} using boxed int", getClass().getName());
        return nextInt();
    }


    @Override
    default void forEach(Block<? super Integer> sink) {
        if (sink instanceof IntBlock) {
            forEach((IntBlock) sink);
        }
        else {
            Iterator.super.forEach(sink);
        }
    }

    //

    int nextInt();

    default void forEach(IntBlock sink) {
        while (hasNext()) {
            sink.applyInt(nextInt());
        }
    }
}

interface IntInfiniteIterator extends IntIterator {
    @Override
    default boolean hasNext() {
        return true;
    }
}