ICU-22789 Add Segmenter API to conveniently wrap BreakIterator

icu4j/main/core/src/main/java/com/ibm/icu/text/segmenter/LocalizedSegmenter.java

@@ -0,0 +1,151 @@
+package com.ibm.icu.text.segmenter;
+
+import com.ibm.icu.text.BreakIterator;
+import com.ibm.icu.util.ULocale;
+import java.util.function.Function;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+
+public class LocalizedSegmenter implements Segmenter {
+
+  private ULocale locale;
+
+  private SegmentationType segmentationType;
+
+  @Override
+  public Segments segment(CharSequence s) {
+    return new LocalizedSegments(s, this);
+  }
+
+  public static Builder builder() {
+    return new Builder();
+  }
+
+  LocalizedSegmenter(ULocale locale, SegmentationType segmentationType) {
+    this.locale = locale;
+    this.segmentationType = segmentationType;
+  }
+
+  /**
+   * @internal
+   * @deprecated This API is ICU internal only.
+   */
+  @Override
+  @Deprecated
+  public BreakIterator getNewBreakIterator() {
+    BreakIterator breakIter;
+    switch (this.segmentationType) {
+      case LINE:
+        breakIter = BreakIterator.getLineInstance(this.locale);
+        break;
+      case SENTENCE:
+        breakIter = BreakIterator.getSentenceInstance(this.locale);
+        break;
+      case WORD:
+        breakIter = BreakIterator.getWordInstance(this.locale);
+        break;
+      case GRAPHEME_CLUSTER:
+      default:
+        breakIter = BreakIterator.getCharacterInstance(this.locale);
+        break;
+    }
+    return breakIter;
+  }
+
+  public enum SegmentationType {
+    GRAPHEME_CLUSTER,
+    WORD,
+    LINE,
+    SENTENCE,
+  }
+
+  public static class Builder {
+
+    private ULocale locale = ULocale.ROOT;
+
+    private SegmentationType segmentationType = SegmentationType.GRAPHEME_CLUSTER;
+
+    Builder() { }
+
+    public Builder setLocale(ULocale locale) {
+      this.locale = locale;
+      return this;
+    }
+
+    public Builder setSegmentationType(SegmentationType segmentationType) {
+      this.segmentationType = segmentationType;
+      return this;
+    }
+
+    public LocalizedSegmenter build() {
+      return new LocalizedSegmenter(this.locale, this.segmentationType);
+    }
+
+  }
+
+  public class LocalizedSegments implements Segments {
+
+    private CharSequence source;
+
+    private LocalizedSegmenter segmenter;
+
+    private BreakIterator breakIter;
+
+    private LocalizedSegments(CharSequence source, LocalizedSegmenter segmenter) {
+      this.source = source;
+      this.segmenter = segmenter;
+      this.breakIter = this.segmenter.getNewBreakIterator();
+    }
+
+    @Override
+    public Stream<CharSequence> subSequences() {
+      return SegmentsImplUtils.subSequences(this.breakIter, this.source);
+    }
+
+    @Override
+    public Segment segmentAt(int i) {
+      return SegmentsImplUtils.segmentAt(this.breakIter, this.source, i);
+    }
+
+    @Override
+    public Stream<Segment> segments() {
+      return SegmentsImplUtils.segments(this.breakIter, this.source);
+    }
+
+    @Override
+    public boolean isBoundary(int i) {
+      return SegmentsImplUtils.isBoundary(this.breakIter, this.source, i);
+    }
+
+    @Override
+    public Stream<Segment> segmentsFrom(int i) {
+      return SegmentsImplUtils.segmentsFrom(this.breakIter, this.source, i);
+    }
+
+    @Override
+    public Stream<Segment> segmentsBefore(int i) {
+      return SegmentsImplUtils.segmentsBefore(this.breakIter, this.source, i);
+    }
+
+    @Override
+    public Function<Segment, CharSequence> segmentToSequenceFn() {
+      return SegmentsImplUtils.segmentToSequenceFn(this.source);
+    }
+
+    @Override
+    public IntStream boundaries() {
+      return SegmentsImplUtils.boundaries(this.breakIter, this.source);
+    }
+
+    @Override
+    public IntStream boundariesAfter(int i) {
+      return SegmentsImplUtils.boundariesAfter(this.breakIter, this.source, i);
+    }
+
+    @Override
+    public IntStream boundariesBackFrom(int i) {
+      return SegmentsImplUtils.boundariesBackFrom(this.breakIter, this.source, i);
+    }
+  }
+
+}

icu4j/main/core/src/main/java/com/ibm/icu/text/segmenter/RuleBasedSegmenter.java

@@ -0,0 +1,115 @@
+package com.ibm.icu.text.segmenter;
+
+import com.ibm.icu.text.BreakIterator;
+import com.ibm.icu.text.RuleBasedBreakIterator;
+import java.util.function.Function;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+
+public class RuleBasedSegmenter implements Segmenter {
+
+  private String rules;
+
+  @Override
+  public Segments segment(CharSequence s) {
+    return new RuleBasedSegments(s, this);
+  }
+
+  public static Builder builder() {
+    return new Builder();
+  }
+
+  RuleBasedSegmenter(String rules) {
+    this.rules = rules;
+  }
+
+  /**
+   * @internal
+   * @deprecated This API is ICU internal only.
+   */
+  @Override
+  @Deprecated
+  public RuleBasedBreakIterator getNewBreakIterator() {
+    return new RuleBasedBreakIterator(this.rules);
+  }
+
+  public static class Builder {
+
+    String rules;
+
+    Builder() { }
+
+    public Builder setRules(String rules) {
+      this.rules = rules;
+      return this;
+    }
+
+    public RuleBasedSegmenter build() {
+      return new RuleBasedSegmenter(this.rules);
+    }
+  }
+
+  public static class RuleBasedSegments implements Segments {
+    private CharSequence source;
+
+    private RuleBasedSegmenter segmenter;
+
+    private BreakIterator breakIter;
+
+    RuleBasedSegments(CharSequence source, RuleBasedSegmenter segmenter) {
+      this.source = source;
+      this.segmenter = segmenter;
+      this.breakIter = this.segmenter.getNewBreakIterator();
+    }
+
+    @Override
+    public Stream<CharSequence> subSequences() {
+      return SegmentsImplUtils.subSequences(this.breakIter, this.source);
+    }
+
+    @Override
+    public Segment segmentAt(int i) {
+      return SegmentsImplUtils.segmentAt(this.breakIter, this.source, i);
+    }
+
+    @Override
+    public Stream<Segment> segments() {
+      return SegmentsImplUtils.segments(this.breakIter, this.source);
+    }
+
+    @Override
+    public boolean isBoundary(int i) {
+      return SegmentsImplUtils.isBoundary(this.breakIter, this.source, i);
+    }
+
+    @Override
+    public Stream<Segment> segmentsFrom(int i) {
+      return SegmentsImplUtils.segmentsFrom(this.breakIter, this.source, i);
+    }
+
+    @Override
+    public Stream<Segment> segmentsBefore(int i) {
+      return SegmentsImplUtils.segmentsBefore(this.breakIter, this.source, i);
+    }
+
+    @Override
+    public Function<Segment, CharSequence> segmentToSequenceFn() {
+      return SegmentsImplUtils.segmentToSequenceFn(this.source);
+    }
+
+    @Override
+    public IntStream boundaries() {
+      return SegmentsImplUtils.boundaries(this.breakIter, this.source);
+    }
+
+    @Override
+    public IntStream boundariesAfter(int i) {
+      return SegmentsImplUtils.boundariesAfter(this.breakIter, this.source, i);
+    }
+
+    @Override
+    public IntStream boundariesBackFrom(int i) {
+      return SegmentsImplUtils.boundariesBackFrom(this.breakIter, this.source, i);
+    }
+  }
+}

icu4j/main/core/src/main/java/com/ibm/icu/text/segmenter/Segmenter.java

@@ -0,0 +1,15 @@
+package com.ibm.icu.text.segmenter;
+
+import com.ibm.icu.text.BreakIterator;
+
+public interface Segmenter {
+  Segments segment(CharSequence s);
+
+  /**
+   * @internal
+   * @deprecated This API is ICU internal only.
+   */
+  @Deprecated
+  BreakIterator getNewBreakIterator();
+
+}