SequenceAndIndices.java

import checkers.interning.quals.*;

import java.util.*;


/**
 * Data structure for storing triples of a sequence and start and
 * end indices, to represent a subsequence.  Requires that the
 * sequence be interned.  Used for interning the repeated finding
 * of subsequences on the same sequence.
 **/
public final class SequenceAndIndices<T extends @Interned Object> {
  public T seq;
  public int start;
  public int end;

  /**
   * @param seq An interned array
   **/
  public SequenceAndIndices (T seq, int start, int end) {
    this.seq = seq;
    this.start = start;
    this.end = end;
    // assert isInterned(seq);
  }

  @SuppressWarnings("unchecked")
  public boolean equals (Object other) {
    if (other instanceof SequenceAndIndices) {
      return equals((SequenceAndIndices<T>) other); // unchecked
    } else {
      return false;
    }
  }

  public boolean equals (SequenceAndIndices<T> other) {
    return (this.seq == other.seq) &&
      this.start == other.start &&
      this.end == other.end;
  }

  public int hashCode() {
    return seq.hashCode() + start * 30 - end * 2;
  }

  // For debugging
  public String toString() {
    // return "SAI(" + start + "," + end + ") from: " + ArraysMDE.toString(seq);
    return "SAI(" + start + "," + end + ") from: " + seq;
  }

}