How to use

TObjectHashingStrategy

in

gnu.trove

/**
 * Locates the index of <tt>obj</tt>.
 *
 * @param obj an <code>Object</code> value
 * @return the index of <tt>obj</tt> or -1 if it isn't in the set.
 */
protected int index(Object obj) {
  int hash, probe, index, length;
  Object[] set;
  Object cur;
  set = _set;
  length = set.length;
  hash = hashingStrategy.computeHashCode(obj) & 0x7fffffff;
  index = hash % length;
  cur = set[index];
  if (cur != null
    && (cur == REMOVED || ! hashingStrategy.equals(cur, obj))) {
    // see Knuth, p. 529
    probe = 1 + (hash % (length - 2));
    do {
      index -= probe;
      if (index < 0) {
        index += length;
      }
      cur = set[index];
    } while (cur != null
         && (cur == REMOVED || ! hashingStrategy.equals(cur, obj)));
  }
  return cur == null ? -1 : index;
}

public static boolean areSignaturesErasureEqual(@NotNull MethodSignature signature1, @NotNull MethodSignature signature2) {
 return METHOD_PARAMETERS_ERASURE_EQUALITY.equals(signature1, signature2);
}

@Override
public int computeHashCode(PsiElement e) {
 if (e instanceof BnfReferenceOrToken || e instanceof BnfLiteralExpression) {
  return e.getText().hashCode();
 }
 return CANONICAL.computeHashCode(e);
}

 @Override
 public boolean equals(PsiElement e1, PsiElement e2) {
  if (e1 instanceof BnfReferenceOrToken && e2 instanceof BnfReferenceOrToken ||
    e1 instanceof BnfLiteralExpression && e2 instanceof BnfLiteralExpression) {
   return e1.getText().equals(e2.getText());
  }
  return CANONICAL.equals(e1, e2);
 }
};

hash = hashingStrategy.computeHashCode(obj) & 0x7fffffff;
index = hash % length;
cur = set[index];
} else if (hashingStrategy.equals(cur, obj)) {
  return -index -1;   // already stored
} else {                // already FULL or REMOVED, must probe
  } while (cur != null
       && cur != REMOVED
       && ! hashingStrategy.equals(cur, obj));
    int firstRemoved = index;
    while (cur != null
        && (cur == REMOVED || ! hashingStrategy.equals(cur, obj))) {
      index -= probe;
      if (index < 0) {