001/*
002 * ModeShape (http://www.modeshape.org)
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *       http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.modeshape.common.math;
017
018import java.math.BigDecimal;
019import java.util.Comparator;
020import java.util.Random;
021import org.modeshape.common.annotation.Immutable;
022
023/**
024 * The {@link MathOperations math operations} for integer numbers.
025 */
026@Immutable
027public class IntegerOperations implements MathOperations<Integer>, Comparator<Integer> {
028
029    @Override
030    public Class<Integer> getOperandClass() {
031        return Integer.class;
032    }
033
034    @Override
035    public Integer add( Integer value1,
036                        Integer value2 ) {
037        if (value1 == null) return value2 != null ? value2 : createZeroValue();
038        if (value2 == null) return value1;
039        return value1 + value2;
040    }
041
042    @Override
043    public Integer subtract( Integer value1,
044                             Integer value2 ) {
045        if (value1 == null) return negate(value2);
046        if (value2 == null) return value1;
047        return value1 - value2;
048    }
049
050    @Override
051    public Integer multiply( Integer value1,
052                             Integer value2 ) {
053        if (value1 == null || value2 == null) return createZeroValue();
054        return value1 * value2;
055    }
056
057    @Override
058    public double divide( Integer value1,
059                          Integer value2 ) {
060        if (value1 == null || value2 == null) throw new IllegalArgumentException();
061        return value1 / value2;
062    }
063
064    @Override
065    public Integer negate( Integer value ) {
066        if (value == null) return createZeroValue();
067        return value * -1;
068    }
069
070    @Override
071    public Integer increment( Integer value ) {
072        if (value == null) return createZeroValue();
073        return value + 1;
074    }
075
076    @Override
077    public Integer maximum( Integer value1,
078                            Integer value2 ) {
079        if (value1 == null) return value2;
080        if (value2 == null) return value1;
081        return Math.max(value1, value2);
082    }
083
084    @Override
085    public Integer minimum( Integer value1,
086                            Integer value2 ) {
087        if (value1 == null) return value2;
088        if (value2 == null) return value1;
089        return Math.min(value1, value2);
090    }
091
092    @Override
093    public int compare( Integer value1,
094                        Integer value2 ) {
095        if (value1 == null) return value2 != null ? -1 : 0;
096        if (value2 == null) return 1;
097        return value1.compareTo(value2);
098    }
099
100    @Override
101    public BigDecimal asBigDecimal( Integer value ) {
102        return value != null ? new BigDecimal(value) : null;
103    }
104
105    @Override
106    public Integer fromBigDecimal( BigDecimal value ) {
107        return value != null ? value.intValue() : null;
108    }
109
110    @Override
111    public Integer createZeroValue() {
112        return 0;
113    }
114
115    @Override
116    public Integer create( int value ) {
117        return value;
118    }
119
120    @Override
121    public Integer create( long value ) {
122        return (int)value;
123    }
124
125    @Override
126    public Integer create( double value ) {
127        return (int)value;
128    }
129
130    @Override
131    public double sqrt( Integer value ) {
132        return Math.sqrt(value);
133    }
134
135    @Override
136    public Comparator<Integer> getComparator() {
137        return this;
138    }
139
140    @Override
141    public Integer random( Integer minimum,
142                           Integer maximum,
143                           Random rng ) {
144        Integer difference = subtract(maximum, minimum);
145        return minimum + rng.nextInt(difference);
146    }
147
148    @Override
149    public double doubleValue( Integer value ) {
150        return value.doubleValue();
151    }
152
153    @Override
154    public float floatValue( Integer value ) {
155        return value.floatValue();
156    }
157
158    @Override
159    public int intValue( Integer value ) {
160        return value.intValue();
161    }
162
163    @Override
164    public long longValue( Integer value ) {
165        return value.longValue();
166    }
167
168    @Override
169    public short shortValue( Integer value ) {
170        return value.shortValue();
171    }
172
173    @Override
174    public int getExponentInScientificNotation( Integer value ) {
175        int v = Math.abs(value);
176        int exp = 0;
177        if (v > 1) {
178            while (v >= 10) {
179                v /= 10;
180                ++exp;
181            }
182        }
183        return exp;
184    }
185
186    @Override
187    public Integer roundUp( Integer value,
188                            int decimalShift ) {
189        if (value == 0) return 0;
190        if (decimalShift >= 0) return value;
191        int shiftedValueP5 = Math.abs(value);
192        for (int i = 0; i != (-decimalShift - 1); ++i)
193            shiftedValueP5 /= 10;
194        shiftedValueP5 += 5l;
195        int shiftedValue = shiftedValueP5 / 10;
196        if (shiftedValue * 10l - shiftedValueP5 >= 5) ++shiftedValue;
197        shiftedValue *= Long.signum(value);
198        for (int i = 0; i != -decimalShift; ++i)
199            shiftedValue *= 10;
200        return shiftedValue;
201    }
202
203    @Override
204    public Integer roundDown( Integer value,
205                              int decimalShift ) {
206        if (value == 0) return 0;
207        if (decimalShift >= 0) return value;
208        int shiftedValue = Math.abs(value);
209        for (int i = 0; i != -decimalShift; ++i)
210            shiftedValue /= 10;
211        shiftedValue *= Long.signum(value);
212        for (int i = 0; i != -decimalShift; ++i)
213            shiftedValue *= 10;
214        return shiftedValue;
215    }
216
217    @Override
218    public Integer keepSignificantFigures( Integer value,
219                                           int numSigFigs ) {
220        if (numSigFigs < 0) return value;
221        if (numSigFigs == 0) return 0;
222        int currentExp = getExponentInScientificNotation(value);
223        int decimalShift = -currentExp + numSigFigs - 1;
224        return roundUp(value, decimalShift);
225    }
226}