1 | /** |
---|
2 | * This software is copyright (c) 2013-2016 by |
---|
3 | * - Institut fuer Deutsche Sprache (http://www.ids-mannheim.de) |
---|
4 | * This is free software. You can redistribute it |
---|
5 | * and/or modify it under the terms described in |
---|
6 | * the GNU General Public License v3 of which you |
---|
7 | * should have received a copy. Otherwise you can download |
---|
8 | * it from |
---|
9 | * |
---|
10 | * http://www.gnu.org/licenses/gpl-3.0.txt |
---|
11 | * |
---|
12 | * @copyright Institut fuer Deutsche Sprache (http://www.ids-mannheim.de) |
---|
13 | * |
---|
14 | * @license http://www.gnu.org/licenses/gpl-3.0.txt |
---|
15 | * GNU General Public License v3 |
---|
16 | */ |
---|
17 | package eu.clarin.sru.server.fcs.parser; |
---|
18 | |
---|
19 | import java.util.Collections; |
---|
20 | import java.util.List; |
---|
21 | |
---|
22 | |
---|
23 | /** |
---|
24 | * base class for FCS-QL expression tree nodes. |
---|
25 | * |
---|
26 | */ |
---|
27 | public abstract class QueryNode { |
---|
28 | protected final QueryNodeType nodeType; |
---|
29 | protected final List<QueryNode> children; |
---|
30 | protected QueryNode parent; |
---|
31 | |
---|
32 | |
---|
33 | /** |
---|
34 | * Constructor. |
---|
35 | * |
---|
36 | * @param nodeType |
---|
37 | * the type of the node |
---|
38 | * @param children |
---|
39 | * the children of this node or <code>null</code> if none |
---|
40 | */ |
---|
41 | protected QueryNode(QueryNodeType nodeType, List<QueryNode> children) { |
---|
42 | this.nodeType = nodeType; |
---|
43 | if ((children != null) && !children.isEmpty()) { |
---|
44 | for (QueryNode child : children) { |
---|
45 | child.setParent(this); |
---|
46 | } |
---|
47 | this.children = Collections.unmodifiableList(children); |
---|
48 | } else { |
---|
49 | this.children = Collections.emptyList(); |
---|
50 | } |
---|
51 | } |
---|
52 | |
---|
53 | |
---|
54 | /** |
---|
55 | * Constructor. |
---|
56 | * |
---|
57 | * @param nodeType |
---|
58 | * the type of the node |
---|
59 | * @param child |
---|
60 | * the child of this node or <code>null</code> if none |
---|
61 | */ |
---|
62 | protected QueryNode(QueryNodeType nodeType, QueryNode child) { |
---|
63 | this.nodeType = nodeType; |
---|
64 | if (child != null) { |
---|
65 | child.setParent(this); |
---|
66 | this.children = Collections.singletonList(child); |
---|
67 | } else { |
---|
68 | this.children = Collections.emptyList(); |
---|
69 | } |
---|
70 | } |
---|
71 | |
---|
72 | |
---|
73 | /** |
---|
74 | * Constructor. |
---|
75 | * |
---|
76 | * @param nodeType |
---|
77 | * the type of the node |
---|
78 | */ |
---|
79 | protected QueryNode(QueryNodeType nodeType) { |
---|
80 | this.nodeType = nodeType; |
---|
81 | this.children = Collections.emptyList(); |
---|
82 | } |
---|
83 | |
---|
84 | |
---|
85 | /** |
---|
86 | * Get the node type of this node. |
---|
87 | * |
---|
88 | * @return the node type |
---|
89 | */ |
---|
90 | public QueryNodeType getNodeType() { |
---|
91 | return nodeType; |
---|
92 | } |
---|
93 | |
---|
94 | |
---|
95 | /** |
---|
96 | * Get the parent node of this node. |
---|
97 | * |
---|
98 | * @return the parent node or <code>null</code> if this is the root node |
---|
99 | */ |
---|
100 | public QueryNode getParent() { |
---|
101 | return parent; |
---|
102 | } |
---|
103 | |
---|
104 | |
---|
105 | /** |
---|
106 | * The children of this node. |
---|
107 | * |
---|
108 | * @return the list of children of this node |
---|
109 | */ |
---|
110 | public List<QueryNode> getChildren() { |
---|
111 | return children; |
---|
112 | } |
---|
113 | |
---|
114 | |
---|
115 | /** |
---|
116 | * Get the number of children of this node. |
---|
117 | * |
---|
118 | * @return the number of children of this node |
---|
119 | */ |
---|
120 | public int getChildCount() { |
---|
121 | final List<QueryNode> children = getChildren(); |
---|
122 | return (children != null) ? children.size() : 0; |
---|
123 | } |
---|
124 | |
---|
125 | |
---|
126 | /** |
---|
127 | * Get a child node by index. |
---|
128 | * |
---|
129 | * @param idx |
---|
130 | * the index of the child node |
---|
131 | * @return the child node of this node or <code>null</code> if index is out |
---|
132 | * of bounds |
---|
133 | */ |
---|
134 | public QueryNode getChild(int idx) { |
---|
135 | final List<QueryNode> children = getChildren(); |
---|
136 | if ((children != null) && !children.isEmpty()) { |
---|
137 | if ((idx >= 0) && (idx < children.size())) { |
---|
138 | return children.get(idx); |
---|
139 | } |
---|
140 | } |
---|
141 | return null; |
---|
142 | } |
---|
143 | |
---|
144 | |
---|
145 | /** |
---|
146 | * Get this first child node. |
---|
147 | * |
---|
148 | * @return the first child node of this node or <code>null</code> if none |
---|
149 | */ |
---|
150 | public QueryNode getFirstChild() { |
---|
151 | return getChild(0); |
---|
152 | } |
---|
153 | |
---|
154 | |
---|
155 | /** |
---|
156 | * Get this last child node. |
---|
157 | * |
---|
158 | * @return the last child node of this node or <code>null</code> if none |
---|
159 | */ |
---|
160 | public QueryNode getLastChild() { |
---|
161 | return getChild(getChildCount() - 1); |
---|
162 | } |
---|
163 | |
---|
164 | |
---|
165 | /** |
---|
166 | * Get a child node of specified type by index. Only child nodes of the |
---|
167 | * requested type are counted. |
---|
168 | * |
---|
169 | * @param clazz |
---|
170 | * the type to nodes to be considered |
---|
171 | * @param idx |
---|
172 | * the index of the child node |
---|
173 | * @return the child node of this node or <code>null</code> if no child was |
---|
174 | * found |
---|
175 | */ |
---|
176 | public <T extends QueryNode> T getChild(Class<T> clazz, int idx) { |
---|
177 | final List<QueryNode> children = getChildren(); |
---|
178 | if (!children.isEmpty()) { |
---|
179 | int pos = 0; |
---|
180 | for (QueryNode child : children) { |
---|
181 | if (clazz.isInstance(child)) { |
---|
182 | if (pos == idx) { |
---|
183 | return clazz.cast(child); |
---|
184 | } |
---|
185 | pos++; |
---|
186 | } |
---|
187 | } |
---|
188 | } |
---|
189 | return null; |
---|
190 | } |
---|
191 | |
---|
192 | |
---|
193 | /** |
---|
194 | * Get a first child node of specified type. |
---|
195 | * |
---|
196 | * @return the child node of this node or <code>null</code> if no child was |
---|
197 | * found |
---|
198 | */ |
---|
199 | public <T extends QueryNode> T getFirstChild(Class<T> clazz) { |
---|
200 | return getChild(clazz, 0); |
---|
201 | } |
---|
202 | |
---|
203 | |
---|
204 | @Override |
---|
205 | public String toString() { |
---|
206 | StringBuilder sb = new StringBuilder(); |
---|
207 | sb.append("(").append(nodeType.toDisplayString()); |
---|
208 | if (!children.isEmpty()) { |
---|
209 | for (QueryNode child : children) { |
---|
210 | sb.append(" ").append(child); |
---|
211 | } |
---|
212 | } |
---|
213 | sb.append(")"); |
---|
214 | return sb.toString(); |
---|
215 | } |
---|
216 | |
---|
217 | |
---|
218 | public abstract void accept(QueryVisitor visitor); |
---|
219 | |
---|
220 | |
---|
221 | protected final void setParent(QueryNode parent) { |
---|
222 | this.parent = parent; |
---|
223 | } |
---|
224 | |
---|
225 | |
---|
226 | protected final void visitAnyNode(QueryVisitor vistor, QueryNode node) { |
---|
227 | if (node instanceof QueryDisjunction) { |
---|
228 | vistor.visit((QueryDisjunction) node); |
---|
229 | } else if (node instanceof QueryGroup) { |
---|
230 | vistor.visit((QueryGroup) node); |
---|
231 | } else if (node instanceof QuerySegment) { |
---|
232 | vistor.visit((QuerySegment) node); |
---|
233 | } else if (node instanceof QuerySequence) { |
---|
234 | vistor.visit((QuerySequence) node); |
---|
235 | } else if (node instanceof ExpressionAnd) { |
---|
236 | vistor.visit((ExpressionAnd) node); |
---|
237 | } else if (node instanceof Expression) { |
---|
238 | vistor.visit((Expression) node); |
---|
239 | } else if (node instanceof ExpressionGroup) { |
---|
240 | vistor.visit((ExpressionGroup) node); |
---|
241 | } else if (node instanceof ExpressionNot) { |
---|
242 | vistor.visit((ExpressionNot) node); |
---|
243 | } else if (node instanceof ExpressionOr) { |
---|
244 | vistor.visit((ExpressionOr) node); |
---|
245 | } else if (node instanceof ExpressionWildcard) { |
---|
246 | vistor.visit((ExpressionWildcard) node); |
---|
247 | } else if (node instanceof SimpleWithin) { |
---|
248 | vistor.visit((SimpleWithin) node); |
---|
249 | } else { |
---|
250 | throw new RuntimeException("unexpected node type: " + |
---|
251 | node.getNodeType()); |
---|
252 | } |
---|
253 | } |
---|
254 | |
---|
255 | } // abstract class QueryNode |
---|