subprojects/store/src/main/java/tools/refinery/store/representation/cardinality/EmptyCardinalityInterval.java


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71

/*
 * SPDX-FileCopyrightText: 2021-2023 The Refinery Authors <https://refinery.tools/>
 *
 * SPDX-License-Identifier: EPL-2.0
 */
package tools.refinery.store.representation.cardinality;

// Singleton implementation, because there is only a single empty interval.
@SuppressWarnings("squid:S6548")
public final class EmptyCardinalityInterval implements CardinalityInterval {
	static final EmptyCardinalityInterval INSTANCE = new EmptyCardinalityInterval();

	private EmptyCardinalityInterval() {
		// Singleton constructor.
	}

	@Override
	public int lowerBound() {
		return 1;
	}

	@Override
	public boolean isEmpty() {
		return true;
	}

	@Override
	public UpperCardinality upperBound() {
		return UpperCardinalities.ZERO;
	}

	@Override
	public CardinalityInterval min(CardinalityInterval other) {
		return this;
	}

	@Override
	public CardinalityInterval max(CardinalityInterval other) {
		return this;
	}

	@Override
	public CardinalityInterval add(CardinalityInterval other) {
		return this;
	}

	@Override
	public CardinalityInterval take(int count) {
		return this;
	}

	@Override
	public CardinalityInterval multiply(CardinalityInterval other) {
		return this;
	}

	@Override
	public CardinalityInterval meet(CardinalityInterval other) {
		return this;
	}

	@Override
	public CardinalityInterval join(CardinalityInterval other) {
		return other;
	}

	@Override
	public String toString() {
		return "error";
	}
}