import java.util.regex.Pattern;

/** A regex pattern implementation which is backed by the {@link Pattern}. */
@ElementTypesAreNonnullByDefault
@GwtIncompatible
final class JdkPattern extends CommonPattern implements Serializable {
  private final Pattern pattern;

  JdkPattern(Pattern pattern) {
    this.pattern = Preconditions.checkNotNull(pattern);
  }

  @Override
  public CommonMatcher matcher(CharSequence t) {

import java.util.regex.Pattern;

/** A regex pattern implementation which is backed by the {@link Pattern}. */
@ElementTypesAreNonnullByDefault
@GwtIncompatible
final class JdkPattern extends CommonPattern implements Serializable {
  private final Pattern pattern;

  JdkPattern(Pattern pattern) {
    this.pattern = Preconditions.checkNotNull(pattern);
  }

  @Override
  public CommonMatcher matcher(CharSequence t) {

  }

  private static final class JdkPatternCompiler implements PatternCompiler {
    @Override
    public CommonPattern compile(String pattern) {
      return new JdkPattern(Pattern.compile(pattern));
    }

    @Override
    public boolean isPcreLike() {
      return true;
    }
  }

   * @throws IllegalArgumentException if {@code separatorPattern} matches the empty string
   */
  @GwtIncompatible // java.util.regex
  public static Splitter on(Pattern separatorPattern) {
    return onPatternInternal(new JdkPattern(separatorPattern));
  }

  /** Internal utility; see {@link #on(Pattern)} instead. */
  static Splitter onPatternInternal(final CommonPattern separatorPattern) {
    checkArgument(