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1 package com.icl.saxon.expr;
2 import com.icl.saxon.Controller;
3 import com.icl.saxon.om.NodeInfo;
4 import com.icl.saxon.om.NodeEnumeration;
5 import com.icl.saxon.sort.Comparer;
6
7
10
11 public class UnionEnumeration implements NodeEnumeration {
12
13 private NodeEnumeration p1;
14 private NodeEnumeration p2;
15 private NodeEnumeration e1;
16 private NodeEnumeration e2;
17 private NodeInfo nextNode1 = null;
18 private NodeInfo nextNode2 = null;
19 private Controller controller;
20
21 public UnionEnumeration(NodeEnumeration p1, NodeEnumeration p2,
22 Controller controller) throws XPathException {
23 this.p1 = p1;
24 this.p2 = p2;
25 this.controller = controller;
26 e1 = p1;
27 e2 = p2;
28
29 if (!e1.isSorted()) {
30 e1 = (new NodeSetExtent(e1, controller)).sort().enumerate();
31 }
32 if (!e2.isSorted()) {
33 e2 = (new NodeSetExtent(e2, controller)).sort().enumerate();
34 }
35
36 if (e1.hasMoreElements()) {
37 nextNode1 = e1.nextElement();
38 }
39 if (e2.hasMoreElements()) {
40 nextNode2 = e2.nextElement();
41 }
42 }
43
44 public boolean hasMoreElements() {
45 return nextNode1!=null || nextNode2!=null;
46 }
47
48 public NodeInfo nextElement() throws XPathException {
49
50
52 if (nextNode1 != null && nextNode2 != null) {
53 int c = controller.compare(nextNode1, nextNode2);
54 if (c<0) {
55 NodeInfo next = nextNode1;
56 if (e1.hasMoreElements()) {
57 nextNode1 = e1.nextElement();
58 } else {
59 nextNode1 = null;
60 }
61 return next;
62
63 } else if (c>0) {
64 NodeInfo next = nextNode2;
65 if (e2.hasMoreElements()) {
66 nextNode2 = e2.nextElement();
67 } else {
68 nextNode2 = null;
69 }
70 return next;
71
72 } else {
73 NodeInfo next = nextNode2;
74 if (e2.hasMoreElements()) {
75 nextNode2 = e2.nextElement();
76 } else {
77 nextNode2 = null;
78 }
79 if (e1.hasMoreElements()) {
80 nextNode1 = e1.nextElement();
81 } else {
82 nextNode1 = null;
83 }
84 return next;
85 }
86 }
87
88
90 if (nextNode1!=null) {
91 NodeInfo next = nextNode1;
92 if (e1.hasMoreElements()) {
93 nextNode1 = e1.nextElement();
94 } else {
95 nextNode1 = null;
96 }
97 return next;
98 }
99 if (nextNode2!=null) {
100 NodeInfo next = nextNode2;
101 if (e2.hasMoreElements()) {
102 nextNode2 = e2.nextElement();
103 } else {
104 nextNode2 = null;
105 }
106 return next;
107 }
108 return null;
109 }
110
111 public boolean isSorted() {
112 return true;
113 }
114
115 public boolean isReverseSorted() {
116 return false;
117 }
118
119 public boolean isPeer() {
120 return false;
121 }
122
123 }
124
125
126
127 |
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