| 43 | int pos; |
| 44 | |
| 45 | @Override |
| 46 | public Item next() throws QueryException { |
| 47 | qc.checkStop(); |
| 48 | |
| 49 | final QueryFocus qf = qc.focus; |
| 50 | Item item = null; |
| 51 | try { |
| 52 | do { |
| 53 | qf.value = values[pos]; |
| 54 | Iter iter = iters[pos]; |
| 55 | if(items[pos]) { |
| 56 | // item-based processing |
| 57 | if(iter == Empty.ITER) { |
| 58 | iters[pos--] = null; |
| 59 | } else { |
| 60 | item = exprs[pos].item(qc, info); |
| 61 | if(item == Empty.VALUE) { |
| 62 | item = null; |
| 63 | pos--; |
| 64 | } else { |
| 65 | iters[pos] = Empty.ITER; |
| 66 | if(pos < el) { |
| 67 | values[++pos] = item; |
| 68 | item = null; |
| 69 | } |
| 70 | } |
| 71 | } |
| 72 | } else { |
| 73 | // iterative processing |
| 74 | if(iter == null) { |
| 75 | iter = exprs[pos].iter(qc); |
| 76 | iters[pos] = iter; |
| 77 | } |
| 78 | item = iter.next(); |
| 79 | if(item == null) { |
| 80 | iters[pos--] = null; |
| 81 | } else if(pos < el) { |
| 82 | values[++pos] = item; |
| 83 | item = null; |
| 84 | } |
| 85 | } |
| 86 | } while(item == null && pos != -1); |
| 87 | return item; |
| 88 | } finally { |
| 89 | qf.value = values[0]; |
| 90 | } |
| 91 | } |
| 92 | }; |
| 93 | } |
| 94 | |