01: /*
02: * $Id: AsciiFunction.java,v 1.8 2005/12/20 18:32:28 ahimanikya Exp $
03: * =======================================================================
04: * Copyright (c) 2002-2005 Axion Development Team. All rights reserved.
05: *
06: * Redistribution and use in source and binary forms, with or without
07: * modification, are permitted provided that the following conditions
08: * are met:
09: *
10: * 1. Redistributions of source code must retain the above
11: * copyright notice, this list of conditions and the following
12: * disclaimer.
13: *
14: * 2. Redistributions in binary form must reproduce the above copyright
15: * notice, this list of conditions and the following disclaimer in
16: * the documentation and/or other materials provided with the
17: * distribution.
18: *
19: * 3. The names "Tigris", "Axion", nor the names of its contributors may
20: * not be used to endorse or promote products derived from this
21: * software without specific prior written permission.
22: *
23: * 4. Products derived from this software may not be called "Axion", nor
24: * may "Tigris" or "Axion" appear in their names without specific prior
25: * written permission.
26: *
27: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28: * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29: * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
30: * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31: * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37: * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38: * =======================================================================
39: */
40:
41: package org.axiondb.functions;
42:
43: import org.axiondb.AxionException;
44: import org.axiondb.DataType;
45: import org.axiondb.FunctionFactory;
46: import org.axiondb.RowDecorator;
47: import org.axiondb.Selectable;
48: import org.axiondb.types.IntegerType;
49: import org.axiondb.util.ValuePool;
50:
51: /**
52: * Returns the Integer value of the left most char of the String
53: *
54: * @version $Revision: 1.8 $ $Date: 2005/12/20 18:32:28 $
55: * @author Sudhendra Seshachala
56: * @author Ahimanikya Satapathy
57: */
58: public class AsciiFunction extends BaseFunction implements
59: ScalarFunction, FunctionFactory {
60:
61: public AsciiFunction() {
62: super ("ASCII");
63: }
64:
65: public ConcreteFunction makeNewInstance() {
66: return new AsciiFunction();
67: }
68:
69: public DataType getDataType() {
70: return RETURN_TYPE;
71: }
72:
73: public Object evaluate(RowDecorator row) throws AxionException {
74: Selectable sel = getArgument(0);
75: Object val = sel.evaluate(row);
76: String intVal = sel.getDataType().toString(val);
77: if (null == intVal) {
78: return null;
79: }
80: return ValuePool.getInt(intVal.charAt(0));
81: }
82:
83: public boolean isValid() {
84: return getArgumentCount() == 1;
85: }
86:
87: private static final DataType RETURN_TYPE = new IntegerType();
88: }
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