Use COALESCE like @Justin provided. With first_value() / last_value() you need to add an ORDER BY clause to the window definition or the order is undefined. You just got lucky in the example, because the rows happen to be in order right after creating the dummy table. Once you add ORDER BY, the default window … Read more
Answering to the main question, someone can access an array in a circular manner using modular arithmetic. That can be achieved in JavaScript with the modulus operator (%) and a workaround. Given an array arr of a length n and a value val stored in it that will be obtained through an access index i, … Read more
The simplest solution would be to keep track of the item size and the number of items, and then create a buffer of the appropriate number of bytes: typedef struct circular_buffer { void *buffer; // data buffer void *buffer_end; // end of data buffer size_t capacity; // maximum number of items in the buffer size_t … Read more
I would use collections.deque with a maxlen arg >>> import collections >>> d = collections.deque(maxlen=10) >>> d deque([], maxlen=10) >>> for i in xrange(20): … d.append(i) … >>> d deque([10, 11, 12, 13, 14, 15, 16, 17, 18, 19], maxlen=10) There is a recipe in the docs for deque that is similar to what you … Read more
My colleague Joe, and I believe we have found a simpler way to solve the same problem. In our solution though instead of extending BaseAdapter we extend ArrayAdapter. The code is as follows : public class CircularArrayAdapter< T > extends ArrayAdapter< T > { public static final int HALF_MAX_VALUE = Integer.MAX_VALUE/2; public final int MIDDLE; … Read more