| /* |
| * 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; |
| |
| /** |
| * Interface for <a href="http://en.wikipedia.org/wiki/Edit_distance">Edit Distances</a>. |
| * |
| * <p> |
| * An edit distance is a formal metric on the Kleene closure ({@code X<sup>*</sup>}) over an |
| * alphabet ({@code X}). Note, that a <a href="https://en.wikipedia.org/wiki/Metric_(mathematics)">metric</a> |
| * on a set {@code S} is a function {@code d: [S * S] -> [0, INFINITY)} such |
| * that the following hold for {@code x,y,z} in |
| * the set {@code S}: |
| * </p> |
| * <ul> |
| * <li>{@code d(x,y) >= 0}, non-negativity or separation axiom</li> |
| * <li>{@code d(x,y) == 0}, if and only if, {@code x == y}</li> |
| * <li>{@code d(x,y) == d(y,x)}, symmetry, and</li> |
| * <li>{@code d(x,z) <= d(x,y) + d(y,z)}, the triangle inequality</li> |
| * </ul> |
| * |
| * |
| * <p> |
| * This is a BiFunction<CharSequence, CharSequence, R>. |
| * The {@code apply} method |
| * accepts a pair of {@link CharSequence} parameters |
| * and returns an {@code R} type similarity score. |
| * </p> |
| * |
| * @param <R> The type of similarity score unit used by this EditDistance. |
| * @since 1.0 |
| */ |
| public interface EditDistance<R> extends SimilarityScore<R> { |
| |
| /** |
| * Compares two CharSequences. |
| * |
| * @param left the first CharSequence |
| * @param right the second CharSequence |
| * @return The similarity score between two CharSequences |
| */ |
| @Override |
| R apply(CharSequence left, CharSequence right); |
| |
| } |