Method next

basex-core/src/main/java/org/basex/query/expr/gflwor/Window.java:109–140

(final QueryContext qc)

      private long spos;

      @Override
      public boolean next(final QueryContext qc) throws QueryException {
        while(true) {
          // find first item
          final Item fst = vals != null ? vals[0] : findStart(qc) ? curr : null;

          // find end item
          if(fst != null) {
            final ValueBuilder vb = new ValueBuilder(qc).add(fst);
            final Item[] st = vals == null ? new Item[] { curr, prev, next } : vals;
            final long ps = vals == null ? pos : spos;
            vals = null;

            while(readNext()) {
              if(start.matches(qc, curr, pos, prev, next)) {
                vals = new Item[] { curr, prev, next };
                spos = pos;
                break;
              }
              vb.add(curr);
            }

            start.bind(qc, st[0], ps, st[1], st[2]);
            qc.set(var, vb.value(Window.this));
            return true;
          }

          // no more iterations from above, we're done here
          if(!prepareNext(qc, sub)) return false;
          vals = null;
        }
      }
    };
  }