diff options
Diffstat (limited to 'subprojects/viatra-runtime-matchers/src/main/java/tools/refinery/viatra/runtime/matchers/util/Accuracy.java')
-rw-r--r-- | subprojects/viatra-runtime-matchers/src/main/java/tools/refinery/viatra/runtime/matchers/util/Accuracy.java | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/subprojects/viatra-runtime-matchers/src/main/java/tools/refinery/viatra/runtime/matchers/util/Accuracy.java b/subprojects/viatra-runtime-matchers/src/main/java/tools/refinery/viatra/runtime/matchers/util/Accuracy.java new file mode 100644 index 00000000..338990ab --- /dev/null +++ b/subprojects/viatra-runtime-matchers/src/main/java/tools/refinery/viatra/runtime/matchers/util/Accuracy.java | |||
@@ -0,0 +1,48 @@ | |||
1 | /******************************************************************************* | ||
2 | * Copyright (c) 2010-2018, Gabor Bergmann, IncQuery Labs Ltd. | ||
3 | * This program and the accompanying materials are made available under the | ||
4 | * terms of the Eclipse Public License v. 2.0 which is available at | ||
5 | * http://www.eclipse.org/legal/epl-v20.html. | ||
6 | * | ||
7 | * SPDX-License-Identifier: EPL-2.0 | ||
8 | *******************************************************************************/ | ||
9 | package tools.refinery.viatra.runtime.matchers.util; | ||
10 | |||
11 | /** | ||
12 | * The degree of accuracy of a cardinality estimate | ||
13 | * @author Gabor Bergmann | ||
14 | * @since 2.1 | ||
15 | */ | ||
16 | public enum Accuracy { | ||
17 | EXACT_COUNT, | ||
18 | BEST_UPPER_BOUND, | ||
19 | BEST_LOWER_BOUND, | ||
20 | APPROXIMATION; | ||
21 | |||
22 | /** | ||
23 | * Partial order comparison. | ||
24 | */ | ||
25 | public boolean atLeastAsPreciseAs(Accuracy other) { | ||
26 | switch (this) { | ||
27 | case EXACT_COUNT: return true; | ||
28 | case APPROXIMATION: return APPROXIMATION == other; | ||
29 | case BEST_UPPER_BOUND: return BEST_UPPER_BOUND == other || APPROXIMATION == other; | ||
30 | case BEST_LOWER_BOUND: return BEST_LOWER_BOUND == other || APPROXIMATION == other; | ||
31 | default: throw new IllegalArgumentException(); | ||
32 | } | ||
33 | } | ||
34 | |||
35 | /** | ||
36 | * @return another accuracy value that is anti-monotonic to this one, | ||
37 | * i.e. an accuracy that should be used in the denominator to obtain a fraction with this accuracy | ||
38 | */ | ||
39 | public Accuracy reciprocal() { | ||
40 | switch(this) { | ||
41 | case APPROXIMATION: return APPROXIMATION; | ||
42 | case BEST_UPPER_BOUND: return BEST_LOWER_BOUND; | ||
43 | case BEST_LOWER_BOUND: return BEST_UPPER_BOUND; | ||
44 | case EXACT_COUNT: return EXACT_COUNT; | ||
45 | default: throw new IllegalArgumentException(); | ||
46 | } | ||
47 | } | ||
48 | } | ||