Moved `FuzzyScore` to original Apache package

2026-04-22 14:51:23 +00:00 · 2022-01-09 14:38:36 +01:00
parent 9b2c86a37b
commit 37cd71328c
2 changed files with 2 additions and 2 deletions
--- a/app/src/main/java/org/apache/commons/text/similarity/FuzzyScore.java
+++ b/app/src/main/java/org/apache/commons/text/similarity/FuzzyScore.java
@@ -0,0 +1,148 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.commons.text.similarity;
+
+import java.util.Locale;
+
+/**
+ * A matching algorithm that is similar to the searching algorithms implemented in editors such
+ * as Sublime Text, TextMate, Atom and others.
+ *
+ * <p>
+ * One point is given for every matched character. Subsequent matches yield two bonus points.
+ * A higher score indicates a higher similarity.
+ * </p>
+ *
+ * <p>
+ * This code has been adapted from Apache Commons Lang 3.3.
+ * </p>
+ *
+ * @since 1.0
+ *
+ * Note: This class was forked from
+ * <a href="https://git.io/JyYJg">
+ *     apache/commons-text (8cfdafc) FuzzyScore.java
+ * </a>
+ */
+public class FuzzyScore {
+
+    /**
+     * Locale used to change the case of text.
+     */
+    private final Locale locale;
+
+
+    /**
+     * This returns a {@link Locale}-specific {@link FuzzyScore}.
+     *
+     * @param locale The string matching logic is case insensitive.
+    A {@link Locale} is necessary to normalize both Strings to lower case.
+     * @throws IllegalArgumentException
+     *         This is thrown if the {@link Locale} parameter is {@code null}.
+     */
+    public FuzzyScore(final Locale locale) {
+        if (locale == null) {
+            throw new IllegalArgumentException("Locale must not be null");
+        }
+        this.locale = locale;
+    }
+
+    /**
+     * Find the Fuzzy Score which indicates the similarity score between two
+     * Strings.
+     *
+     * <pre>
+     * score.fuzzyScore(null, null)                          = IllegalArgumentException
+     * score.fuzzyScore("not null", null)                    = IllegalArgumentException
+     * score.fuzzyScore(null, "not null")                    = IllegalArgumentException
+     * score.fuzzyScore("", "")                              = 0
+     * score.fuzzyScore("Workshop", "b")                     = 0
+     * score.fuzzyScore("Room", "o")                         = 1
+     * score.fuzzyScore("Workshop", "w")                     = 1
+     * score.fuzzyScore("Workshop", "ws")                    = 2
+     * score.fuzzyScore("Workshop", "wo")                    = 4
+     * score.fuzzyScore("Apache Software Foundation", "asf") = 3
+     * </pre>
+     *
+     * @param term a full term that should be matched against, must not be null
+     * @param query the query that will be matched against a term, must not be
+     *            null
+     * @return result score
+     * @throws IllegalArgumentException if the term or query is {@code null}
+     */
+    public Integer fuzzyScore(final CharSequence term, final CharSequence query) {
+        if (term == null || query == null) {
+            throw new IllegalArgumentException("CharSequences must not be null");
+        }
+
+        // fuzzy logic is case insensitive. We normalize the Strings to lower
+        // case right from the start. Turning characters to lower case
+        // via Character.toLowerCase(char) is unfortunately insufficient
+        // as it does not accept a locale.
+        final String termLowerCase = term.toString().toLowerCase(locale);
+        final String queryLowerCase = query.toString().toLowerCase(locale);
+
+        // the resulting score
+        int score = 0;
+
+        // the position in the term which will be scanned next for potential
+        // query character matches
+        int termIndex = 0;
+
+        // index of the previously matched character in the term
+        int previousMatchingCharacterIndex = Integer.MIN_VALUE;
+
+        for (int queryIndex = 0; queryIndex < queryLowerCase.length(); queryIndex++) {
+            final char queryChar = queryLowerCase.charAt(queryIndex);
+
+            boolean termCharacterMatchFound = false;
+            for (; termIndex < termLowerCase.length()
+                    && !termCharacterMatchFound; termIndex++) {
+                final char termChar = termLowerCase.charAt(termIndex);
+
+                if (queryChar == termChar) {
+                    // simple character matches result in one point
+                    score++;
+
+                    // subsequent character matches further improve
+                    // the score.
+                    if (previousMatchingCharacterIndex + 1 == termIndex) {
+                        score += 2;
+                    }
+
+                    previousMatchingCharacterIndex = termIndex;
+
+                    // we can leave the nested loop. Every character in the
+                    // query can match at most one character in the term.
+                    termCharacterMatchFound = true;
+                }
+            }
+        }
+
+        return score;
+    }
+
+    /**
+     * Gets the locale.
+     *
+     * @return The locale
+     */
+    public Locale getLocale() {
+        return locale;
+    }
+
+}