src/main/java/com/github/fge/grappa/parsers/BaseActions.java
public <E extends V> E peekAs(final Class<E> c)
    {
        return c.cast(peek());
    }
public <E extends V> E peekAs(final Class<E> c)
    {
        return c.cast(peek());
    }
Returns and casts the value at the top of the value stack without
removing it

@param c the class to cast to
@param <E> type of the class
@return the value

@see #peek()