port SudachiPy PosMatcher to Java

src/main/java/com/worksap/nlp/sudachi/Dictionary.java

@@ -16,8 +16,12 @@
 
 package com.worksap.nlp.sudachi;
 
+import com.worksap.nlp.sudachi.dictionary.POS;
+
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.List;
+import java.util.function.Predicate;
 
 /**
  * A lexicon and a grammar for morphological analysis.
@@ -64,4 +68,48 @@ public interface Dictionary extends AutoCloseable {
      *             if {@code posId} is out of the range
      */
     public List<String> getPartOfSpeechString(short posId);
+
+    /**
+     * Create a POS matcher that will match any of POS for which the passed
+     * predicate returns true. PosMatcher will be much faster than doing string
+     * comparison on POS objects.
+     *
+     * @param predicate
+     *            returns true if the POS is needed
+     * @return PosMatcher object that mirrors behavior of the predicate
+     */
+    PosMatcher posMatcher(Predicate<POS> predicate);
+
+    /**
+     * Create a POS matcher that will mirror matching behavior of passed list of
+     * partially-defined POS.
+     * 
+     * @param posList
+     *            list of partially defined part-of-speech objects
+     * @return mirroring PosMatcher object
+     * @see PartialPOS
+     */
+    default PosMatcher posMatcher(Iterable<PartialPOS> posList) {
+        return posMatcher(posRepr -> {
+            for (PartialPOS p : posList) {
+                if (p.matches(posRepr)) {
+                    return true;
+                }
+            }
+            return false;
+        });
+    }
+
+    /**
+     * Create a POS matcher that will mirror matching behavior of passed list of
+     * partially-defined POS.
+     * 
+     * @param posList
+     *            list of partially defined part-of-speech objects
+     * @return mirroring PosMatcher object
+     * @see PartialPOS
+     */
+    default PosMatcher posMatcher(PartialPOS... posList) {
+        return posMatcher(Arrays.asList(posList));
+    }
 }

src/main/java/com/worksap/nlp/sudachi/JapaneseDictionary.java

@@ -26,6 +26,8 @@
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
+import java.util.function.Predicate;
+import java.util.stream.IntStream;
 
 public class JapaneseDictionary implements Dictionary, DictionaryAccess {
 
@@ -166,4 +168,12 @@ public LexiconSet getLexicon() {
         return lexicon;
     }
 
+    @Override
+    public PosMatcher posMatcher(Predicate<POS> predicate) {
+        GrammarImpl grammar = getGrammar();
+        int numPos = grammar.getPartOfSpeechSize();
+        int[] ids = IntStream.range(0, numPos).filter(id -> predicate.test(grammar.getPartOfSpeechString((short) id)))
+                .toArray();
+        return new PosMatcher(ids, this);
+    }
 }

src/main/java/com/worksap/nlp/sudachi/PartialPOS.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2022 Works Applications Co., Ltd.
+ *
+ * Licensed 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 com.worksap.nlp.sudachi;
+
+import com.worksap.nlp.sudachi.dictionary.POS;
+
+import java.util.AbstractList;
+import java.util.Arrays;
+import java.util.List;
+
+public class PartialPOS extends AbstractList<String> {
+    private final List<String> data;
+
+    public PartialPOS(List<String> data) {
+        if (data.size() == 0) {
+            throw new IllegalArgumentException("Partial POS must have at least 1 component");
+        }
+        if (data.size() > POS.DEPTH) {
+            throw new IllegalArgumentException("Partial POS can have at most 6 components, was " + data);
+        }
+        for (String component : data) {
+            if (component != null && component.length() > POS.MAX_COMPONENT_LENGTH) {
+                throw new IllegalArgumentException("Component length can't be more than " + POS.MAX_COMPONENT_LENGTH
+                        + ", was " + component.length() + ":" + component);
+            }
+        }
+        this.data = data;
+    }
+
+    public PartialPOS(String... data) {
+        this(Arrays.asList(data));
+    }
+
+    @Override
+    public String get(int index) {
+        return data.get(index);
+    }
+
+    @Override
+    public int size() {
+        return data.size();
+    }
+
+    boolean matches(POS pos) {
+        for (int level = 0; level < data.size(); ++level) {
+            String s = data.get(level);
+            if (s == null) {
+                continue;
+            }
+            if (!s.equals(pos.get(level))) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    @Override
+    public String toString() {
+        return String.join(",", data);
+    }
+
+    public static PartialPOS of(String... parts) {
+        return new PartialPOS(parts);
+    }
+}

src/main/java/com/worksap/nlp/sudachi/PosMatcher.java

@@ -0,0 +1,155 @@
+/*
+ * Copyright (c) 2022 Works Applications Co., Ltd.
+ *
+ * Licensed 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 com.worksap.nlp.sudachi;
+
+import com.worksap.nlp.sudachi.dictionary.POS;
+
+import java.util.BitSet;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+import java.util.function.Predicate;
+import java.util.stream.IntStream;
+
+/**
+ * API for checking if a morpheme belongs to a set of part of speech. Use
+ * factory methods of {@link Dictionary} object to create instances.
+ * 
+ * @see Dictionary#posMatcher(Predicate)
+ * @see Dictionary#posMatcher(Iterable)
+ */
+public class PosMatcher implements Predicate<Morpheme>, Iterable<POS> {
+    private final BitSet matching;
+    private final JapaneseDictionary dictionary;
+
+    /**
+     * Creates a PosMatcher for a given Dictionary and list of POS id. This is a
+     * low-level API, use factory method on {@link Dictionary} instead
+     * 
+     * @param ids
+     *            list of POS ids
+     * @param dictionary
+     *            related dictionary
+     */
+    public PosMatcher(int[] ids, JapaneseDictionary dictionary) {
+        BitSet bits = new BitSet();
+        for (int id : ids) {
+            bits.set(id);
+        }
+        matching = bits;
+        this.dictionary = dictionary;
+    }
+
+    private PosMatcher(BitSet data, JapaneseDictionary dictionary) {
+        this.matching = data;
+        this.dictionary = dictionary;
+    }
+
+    /**
+     * Returns a PosMatcher which matches POS present in any of matchers
+     * 
+     * @param other
+     *            second matcher
+     * @return PosMatcher which matches union of POS tags
+     */
+    public PosMatcher union(PosMatcher other) {
+        checkCompatibility(other);
+        BitSet merged = new BitSet();
+        merged.or(matching);
+        merged.or(other.matching);
+        return new PosMatcher(merged, dictionary);
+    }
+
+    /**
+     * Returns a PosMatcher which matches POS present in both of matchers
+     * 
+     * @param other
+     *            second matcher
+     * @return PosMatcher which matches intersection of POS tags
+     */
+    public PosMatcher intersection(PosMatcher other) {
+        checkCompatibility(other);
+        BitSet merged = new BitSet();
+        merged.or(matching);
+        merged.and(other.matching);
+        return new PosMatcher(merged, dictionary);
+    }
+
+    /**
+     * Returns a PosMatcher for POS not present in current PosMatcher
+     * 
+     * @return PosMatcher which is inverse of this
+     */
+    public PosMatcher invert() {
+        // bitset can be shorter than number of ids, so we create the full id range and
+        // filter matching items
+        int[] indices = IntStream.range(0, dictionary.getPartOfSpeechSize()).filter(idx -> !matching.get(idx))
+                .toArray();
+        return new PosMatcher(indices, dictionary);
+    }
+
+    private void checkCompatibility(PosMatcher other) {
+        if (dictionary != other.dictionary) {
+            throw new IllegalArgumentException("PosMatchers are using different dictionaries");
+        }
+    }
+
+    /**
+     * Checks that {@link Morpheme} matches the POS configuration. It is incorrect
+     * to pass the Morpheme produced from other {@link Dictionary} than the one
+     * which was used to create the current instance of {@link PosMatcher}.
+     *
+     * When assertions are enabled, this method checks if Morpheme was produced by
+     * the same dictionary.
+     * 
+     * @param morpheme
+     *            the input argument
+     * @return true if morpheme matches the current configuration, false otherwise
+     */
+    @Override
+    public boolean test(Morpheme morpheme) {
+        assert ((MorphemeImpl) morpheme).list.grammar == dictionary.grammar;
+        return matching.get(morpheme.partOfSpeechId());
+    }
+
+    /**
+     * Iterates POS tags which are matched by this matcher
+     * 
+     * @return Iterator for POS tags
+     */
+    @Override
+    public Iterator<POS> iterator() {
+        return new Iterator<POS>() {
+            private int index = matching.nextSetBit(0);
+
+            @Override
+            public boolean hasNext() {
+                return index >= 0;
+            }
+
+            @Override
+            public POS next() {
+                if (index < 0) {
+                    throw new NoSuchElementException();
+                }
+                short posId = (short) index;
+                POS result = dictionary.getGrammar().getPartOfSpeechString(posId);
+                index = matching.nextSetBit(index + 1);
+                return result;
+            }
+        };
+    }
+}